[ccc]

haveing an old car is a leap of faith sometimes. your rear gear and trans optons will afect how high your rpm will go with light and heavy throttle.tune your engine and repair your carb as needed and it should be fine provideing the engine is sound and carries good oil pressure (45 psi warm) i just went from 342s to 273s and noticed a big differance on how far the rpm will go without pushing it between shifts and how much longer it takes to hit the 6500 revlimiter at wide open throttle.and i am running a little over 400 hp right now.a stock 130 /190 hp mid 80s to mid 90 s truck motor can seem sluggish in a car with a non od trans and tall gears. it doesnt mean there is a problem just the way your set up worked out.

 

[ccc]

already made a deal on them and the posi to another poster. but i have several sets of gears. the truck motors are great on torque but short on hp and rpm range. thier done at about 4500,will go further but make little power.no sense stressing an engine past where its designed to run.

 

[ccc]

limited slip would spin both tires, limited slip and positraction are the same thing just a play on words. a couple co. make true lockers but most are limited slip diffs of one make up or another. i personally wont use any posi unit that doesnt use clutches, the thorsen and auburn style cant be rebuilt when worn ,they must be replaced. a big expense compared to 70$ for clutches

 

[ccc]

you have to remember your car tries to push with both tires.and sometimes a open rear will spin both for a few seconds then the right will spin. my malibu would spin both half of the time when i did burnouts and it was an open rear. it just had very close weight dist.and good traction.if you hear no noise it is probably fine. my wife broke the rear in the malibu and you knew it for sure. i heard it before i could see her comeing.