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: Good heads for 305?


m6 c5
01-19-2012, 08:45 PM
Alright from what Ive read it looks like vortec heads are a good upgrade but it sounds like I would need to get a new intake, is that true? I also saw something about double hump heads, Im not sure what casting those would be or what they would even come out of so if someone has that info I would appreciate it. Are there any other good heads I can pick up at a junkyard that would be an improvement and a direct bolt on? Id love to have casting numbers and years if possible. Thanks.

87next2last1
01-19-2012, 08:52 PM
Yes, you will need a different intake for vortec heads !! Double hump heads are great but they say they are old technology 40+ years !! The Vortec heads are new technology !! But there is a bunch of new aftermarket heads to get to !!:dontknow:

m6 c5
01-19-2012, 09:06 PM
Yes, you will need a different intake for vortec heads !! Double hump heads are great but they say they are old technology 40+ years !! The Vortec heads are new technology !! But there is a bunch of new aftermarket heads to get to !!:dontknow:

Well I dont really have the money to spend on new heads so I was hoping to get some better flowing heads for cheap. Id just like to get a little bit more performance out of the engine while its out.
If I got the vortec heads where would I get an intake that I could bolt my q jet up to?

spencersr
01-19-2012, 09:23 PM
You can use 305 vortrch heads with a stock vortech intake they make adapters. Get a but motor or dremel and port match the gasket and you'll notice the differnce if only in your mind ha-ha. I port matched the intake on my lt1 fleetwood caddy and I noticed it

m6 c5
01-19-2012, 09:33 PM
You can use 305 vortrch heads with a stock vortech intake they make adapters. Get a but motor or dremel and port match the gasket and you'll notice the differnce if only in your mind ha-ha. I port matched the intake on my lt1 fleetwood caddy and I noticed it

Ok so do I have to get the heads off of a 305 or can I use ones off of a 350? If Im not mistaken the vortec heads I can use are 92-98 and off of a truck correct?

jlcustomz
01-20-2012, 05:47 AM
If you have one in your area, talk to a local head rebuilder. Some of the mid/later 80's 305 engines were referred to as H.O. & had slightly better flowing heads. In the early 90's, I got a set disassembled from a rebuilder, did my own mild porting/ cleanup job & had them do the 3 angle valve job &reassembly with 10 degree retainers. Noticeable difference.

darbysan
01-20-2012, 07:48 AM
Matt, JL is on the right track. The HO 305's were about the best head produced before the vortec's came out ( Last digits of the casting numbers were 601 or 416 for perimeter bolt VC, and 081 for Center Bolt). The 081's will work with your current intake with no mods, but you can modify the two center intake manifold bolts and use the other two numbers ( with new VC). There was also a 350 version of this head ( 083's- sometimes reffered to as the L98 head). You can find the 305 heads most easily on MonteCarlo SS or F-bodies with the HO engine. They also came on the TPI engines ( Not the TBI thought- those are swirl port heads). Stock, they are pretty good. With porting, they flow about the same as the Vortecs, but without the need for special intakes.

here's an ad on Ebay for some 081 heads. They are overpriced ( IMO). Used, you should be able to pick these up for $100-$200/pr. Junk yard Prices might be lower. A good valve job should run maybe another $200.

By the way, the Vortec you were talking about came out in '96-'99, used on trucks and vans ( Last digits of the casting number would be 906 or 062). Look for 3 sharp peaks on the front end of the head used as an identifier.

m6 c5
01-20-2012, 01:39 PM
Matt, JL is on the right track. The HO 305's were about the best head produced before the vortec's came out ( Last digits of the casting numbers were 601 or 416 for perimeter bolt VC, and 081 for Center Bolt). The 081's will work with your current intake with no mods, but you can modify the two center intake manifold bolts and use the other two numbers ( with new VC). There was also a 350 version of this head ( 083's- sometimes reffered to as the L98 head). You can find the 305 heads most easily on MonteCarlo SS or F-bodies with the HO engine. They also came on the TPI engines ( Not the TBI thought- those are swirl port heads). Stock, they are pretty good. With porting, they flow about the same as the Vortecs, but without the need for special intakes.

here's an ad on Ebay for some 081 heads. They are overpriced ( IMO). Used, you should be able to pick these up for $100-$200/pr. Junk yard Prices might be lower. A good valve job should run maybe another $200.

By the way, the Vortec you were talking about came out in '96-'99, used on trucks and vans ( Last digits of the casting number would be 906 or 062). Look for 3 sharp peaks on the front end of the head used as an identifier.

Thanks, thats exactly what I was looking for. So from what you are saying I would be better off with HO 305 heads than 96-98 vortec heads as the 305 heads flow about the same without having to get a new intake?

darbysan
01-20-2012, 01:58 PM
Thanks, thats exactly what I was looking for. So from what you are saying I would be better off with HO 305 heads than 96-98 vortec heads as the 305 heads flow about the same without having to get a new intake?

They would flow about the same with some porting work done to them. You could use your stock intake. The Vortecs flow better out of the box, but also have larger combustion chambers, which reduce your compression ratio ( and hence lower your power). You can use very thin gaskets to try and offset some of the compression loss. Vortec Carb Intakes can be found on Ebay for about $100.

You may want to check the heads you have now. IIRC, the casting was the same for the L69 and base engines. The major difference was the L69 head got larger intake valves. If that is the case, you can have your valve size increased when you do a valve job, some porting, and be good to go.

While you are that far in to the engine, I would also change the cam to something a little better than stock, and replace the Timing Chain ( good insurance). Your '87 block may already be machined for Roller Lifters. If so, a good used LT1 cam is a great upgrade. You should be able to get the cam, lifters, pushrods, retainers, and dogbones all for probabaly $100-$125.

Look at your lifter valley under the intake manifold. There should be 3 raised bumps running down the valley. These get drilled and tapped for the spider hold down. I did mine with a hand drill and tap. If it's roller ready, the front of the motor, where the cam resides, should have two holes machined in the face of the block to hold the cam retainer. A new Flat Tappet cam and Lifters (always change the lifters with the Flatt tappet cam) will probably run about the same amount (maybe $25 more) and be nearly as effective.

In reality, you'll get more performance improvement from the cam than any other change, as long as you have good flowing exhaust and no restrictions on the intake. Better flowing heads always help. You'll like the cam performance.

DOUG213XRJ
01-20-2012, 03:56 PM
Hey Matt. I also agree with getting a set of 305 H/O heads. I have #14014416 (1980-1999) on my H/O and they work great. Dont know much about the 305 Vortec heads but if there like the 350 vortec heads they would make a great upgrade for your 305.

Doug

m6 c5
01-20-2012, 06:25 PM
They would flow about the same with some porting work done to them. You could use your stock intake. The Vortecs flow better out of the box, but also have larger combustion chambers, which reduce your compression ratio ( and hence lower your power). You can use very thin gaskets to try and offset some of the compression loss. Vortec Carb Intakes can be found on Ebay for about $100.

You may want to check the heads you have now. IIRC, the casting was the same for the L69 and base engines. The major difference was the L69 head got larger intake valves. If that is the case, you can have your valve size increased when you do a valve job, some porting, and be good to go.

While you are that far in to the engine, I would also change the cam to something a little better than stock, and replace the Timing Chain ( good insurance). Your '87 block may already be machined for Roller Lifters. If so, a good used LT1 cam is a great upgrade. You should be able to get the cam, lifters, pushrods, retainers, and dogbones all for probabaly $100-$125.

Look at your lifter valley under the intake manifold. There should be 3 raised bumps running down the valley. These get drilled and tapped for the spider hold down. I did mine with a hand drill and tap. If it's roller ready, the front of the motor, where the cam resides, should have two holes machined in the face of the block to hold the cam retainer. A new Flat Tappet cam and Lifters (always change the lifters with the Flatt tappet cam) will probably run about the same amount (maybe $25 more) and be nearly as effective.

In reality, you'll get more performance improvement from the cam than any other change, as long as you have good flowing exhaust and no restrictions on the intake. Better flowing heads always help. You'll like the cam performance.

Well it sounds like I would be better off getting the later heads as I was planning on getting the heads resurfaced anyways to be sure they are true so I could have them milled down enough to keep the compression up there. Also they should give me a little more PTV correct? Im not sure how much I have as it is but the pistons already have valve reliefs from the factory so I cant imagine there is too much room for a cam with more lift.
I was already planning on a cam upgrade and possibly one from an Lt1 or Lt4. I suppose you cant tell from the picture but I guess its worth asking if you can see the cam retainer holes.http://i1025.photobucket.com/albums/y320/mattbhill/El%20camino/DSC_1971.jpg
Also I assume the three bumps in the center are what you are talking about that need to be drilled and tapped for the spider. Ive never heard of anything like that so I dont think I know what it is.http://i1025.photobucket.com/albums/y320/mattbhill/El%20camino/DSC_1962.jpg

steelybill
01-20-2012, 10:55 PM
If you look at the links posted on my question about Vortec heads, there's info there to help you, with part numbers, etc. Be careful when selecting a camshaft, with low compression heads & pistons. Too much duration will make a dog of the engine.

http://www.elcaminocentral.com/showthread.php?t=47329

darbysan
01-21-2012, 09:03 AM
For roller cams, you have the following parts:
Roller Lifters (16)- take the place of Flat Tappet Lifters. These need to be held from rotating, so they have 'Dogbones" that slip over two adjoining lifters to keep them from turning. You will have 8 dogbones. The spider ( Holddown) bolts to the lifter valley with 3 bolts, and has 8 arms that hold the Dogbones in place. You can see samples of these items in this Ebay Transaction
http://www.ebay.com/itm/96-02-5-7-350-CHEVY-ROLLER-CAM-LIFTERS-HOLD-DOWN-PLATES-/400154871758?item=400154871758&vxp=mtr#ht_500wt_969

Here's a picture of mine installed:
http://i300.photobucket.com/albums/nn12/darbysan/CIMG2720.jpg

You will also need Pushrods that match with the roller lifters.

The cam is held into the block with a retainer plate and two screws. The holes for these two screws will be found behind the large sprocket on the front of your engine. The sprockets and chain are different for a roller engine, so if you go that direction be sure to specify for a roller cam. If you buy the GMPP roller cam timing set, it comes with the retainer plate and screws.

steelybill
01-21-2012, 08:47 PM
I just received a flyer from Summit racing, and they have a sale on new GM Vortec heads, for $309.95 each. 64 CC chambers, 1.94/1.5 valves, max lift .480"
They require self-aligning rockers, & Vortec intake of course.
There's a number on the page...NAL-12558060, which I don't know if it's the part number.

m6 c5
01-22-2012, 02:38 PM
I just received a flyer from Summit racing, and they have a sale on new GM Vortec heads, for $309.95 each. 64 CC chambers, 1.94/1.5 valves, max lift .480"
They require self-aligning rockers, & Vortec intake of course.
There's a number on the page...NAL-12558060, which I don't know if it's the part number.

Yea thats a little to high for my budget build... I could probably swing 3-400 on the pair but for just one, its just more than I want to spend.

m6 c5
01-22-2012, 04:02 PM
Ok I found some 99 305 vortec heads, are these comparable to the 350 vortecs? And does anyone know what the casting number should be just so I can verify.

darbysan
01-23-2012, 08:36 AM
305 Vortecs, the casting number ends in 059 ( some end in 520). Not the same design as the 350 Vortecs, but not bad. Still requires a vortec style intake manifold. Smaller combustion chamber, so higher compression ratio than the L31 vortecs. All in all, a good budget choice if the price is right.

old_coot
01-23-2012, 09:17 AM
I don't know what your total budget is for this rebuild but I can assure you it's going to be more than you plan....I've done it at least 100 times and haven't been able to stay in budget yet so having said that let me offer a little advise for an old codger thats been at this hobby for a lot of years....If youwant a little more performance (and I agree the 305 needs some help) why not consider a complete engine replacement with a crate for the gm dealer. A goodwrench 350 will have everything new and matched parts with a nationwide warranty cheaper than you can build one.Here is just one example:
http://sdparts.com/category/gm-goodwrench-350-crate-engine-and-engine-kits.

All the accessories from your current 305 ought to swap over and you will be on the road and way ahead of the game. A305 can be made to run decent for about twice that price.........Dan

m6 c5
01-23-2012, 09:30 AM
I don't know what your total budget is for this rebuild but I can assure you it's going to be more than you plan....I've done it at least 100 times and haven't been able to stay in budget yet so having said that let me offer a little advise for an old codger thats been at this hobby for a lot of years....If youwant a little more performance (and I agree the 305 needs some help) why not consider a complete engine replacement with a crate for the gm dealer. A goodwrench 350 will have everything new and matched parts with a nationwide warranty cheaper than you can build one.Here is just one example:
http://sdparts.com/category/gm-goodwrench-350-crate-engine-and-engine-kits.

All the accessories from your current 305 ought to swap over and you will be on the road and way ahead of the game. A305 can be made to run decent for about twice that price.........Dan

Hmmmm, didnt realize you could get a new engine that cheap. You dont happen to know if I can still use my factory intake do you, because from the looks of it it comes with everything but the intake, carb and accessories.

old_coot
01-23-2012, 11:45 AM
Yes you can use the intake, fuel pump, and all front accessories and pullys. I would install a new fuel pump though and you may have to for warranty issues...but yeah they can build new cheaper than we can overhaul a used engine.

m6 c5
01-23-2012, 01:39 PM
Yes you can use the intake, fuel pump, and all front accessories and pullys. I would install a new fuel pump though and you may have to for warranty issues...but yeah they can build new cheaper than we can overhaul a used engine.

Yea, thats actually around what I was wanting to spend in the end, 1500-2000 over a few months is a lot easier than 1500 at once. Plus I still want to get some longtubes but that may have to wait, still havent been able to find a decent pair anyways though.

old_coot
01-24-2012, 06:37 AM
Yea, thats actually around what I was wanting to spend in the end, 1500-2000 over a few months is a lot easier than 1500 at once. Plus I still want to get some longtubes but that may have to wait, still havent been able to find a decent pair anyways though.

Save until you can purchase the engine, because then you end up with a new 350 making nearly an extra hundred horsepower plus gobs more torque and a 3 year 100,000 mile warranty that you won't have with the rebuilt 305. Plus, down the road if you decide to add even more performance goodies, with the four bolt main block and good rods this engine has you have a much better platform to start with.

m6 c5
01-24-2012, 07:22 AM
Save until you can purchase the engine, because then you end up with a new 350 making nearly an extra hundred horsepower plus gobs more torque and a 3 year 100,000 mile warranty that you won't have with the rebuilt 305. Plus, down the road if you decide to add even more performance goodies, with the four bolt main block and good rods this engine has you have a much better platform to start with.

Yea thats what Im planning, too bad it doesnt make a little more power because I would like to have a nice vehicle to tow with. But then again Ive only recently towed with a vehicle that has 275 275 so the 300 ft lbs should help out.

TheHeartbeat
01-26-2012, 03:43 PM
Find some 283 heads.
Enjoy the amazing compression ratio and price.
Thank me later. :D

m6 c5
01-27-2012, 10:07 AM
Find some 283 heads.
Enjoy the amazing compression ratio and price.
Thank me later. :D

283 heads? This is the first Ive heard of these.

steelybill
01-27-2012, 09:26 PM
The early 283 heads do not have accessory mounting bosses/holes. Not sure what year they went to the later castings with the mount holes. Small ports in those too, from what I remember....and small valves except the so-called "power-pack" type & Corvette.

old_coot
01-30-2012, 06:42 AM
Trust me, going from the 145 hp to that engine will be like turning on another engine, but a lot more power is available with just a cam and set of aluminum head to kick the compression up a point or more...plus the bottom end of that engine is built to survive more power. Thats what I meant by if down the road you want more power you won't have to mess with the short block. I'm guessing it will keep you happy as is for a few years.......Dan

steelybill
01-30-2012, 04:03 PM
What Dan said......:smileyb: