Greetings all! I looked for the answers in the fourm search - but didn't find what I was looking for. I'm now the owner of a 83' El Camino. It had new monroe air shocks in 02' , maby 20 k miles on them since. What are the air pressure limits - min/ max & avg settings? It had 70 psi when I got it & I lowered that to 40 for a smoother / less floaty ride. Also provided everything is in fair shape - how much weight can I haul with her? What would I pump the shocks up to to haul a 600lb. item?

It has a semi built 350 & a 4 speed 700R trans. installed - on the trans. if I were towing or performance testing - should I leave it in 3rd gear - because believe in other 4 speed autos I've seen the 4th gear it thought of as a Drive/ overdrive gearing. Would this be correct?

I have a 70 with a 700R4.

I think my aftermarket air shocks are rated up to something like 165 PSI.

As far as the trans is concerned, I think there are four factors (at least) to take into consideration:

First, is your rear gear ratio. If it's numerically low (like in the high twos or very low threes) then third will never wind out enough with WOT to get into 4th [and still be reasonably safe on the highway].

Second, Check with the experts (please don't take my word for it ) but I believe there may be something built into a 700R4 to prevent upshift into 4th at WOT. It might be to prevent TCC lockup. I forget.

Third, the 3-4 shift in an O'D trans is a long jump, and therefore hammers the transmission's clutches, sprags etc. fairly hard if you have a high output motor. If your trans isn't ready/built for this is could cause problems.

Fourth, most late model transmissions are more sensitive to heat buildup than are the early model PwrGlide/TH350/400s. It's a good idea to ensure you have a trans cooler if you're going to romp on it often, or for any length of time.

Hope it helps.