I have a 71 Nova with competition engineering shocks with coil springs over them. It's a ladder bar car the length of the shock is 16 in Long and 10.41 collapsed. Any suggestions on what length of shock and spring rate I should use. I was looking at the qa1 u.s. 502 shocks and I have a 150 spring rate already.

qa1s are junk same as your current shock

Give me a call or text. 484-529-3501. I may have something for you. Just need to know what ride height # you are looking for to better assist you. As stated above the QA1 isn't really an upgrade over what you have.

Spend a bit more and get a better shock like Afco. It will pay off in the end. Shocks are not where i look to save a dime.

150# spring seems excessive, but then again I'm only recalling what was on my 72 Nova.

I switched out my QA1's (double adjustable front, single rear) on my Nova for Afco's. I picked up .04 in the 60ft. I dont recall what spring is on my Nova but planned on scaling and aligning it this weekend so I will check the spring rate.

Afco's cost more but way worth it in the long run. You need a shock that will repeat, over and over again. I would figure out a way to put an Afco 6855 single adjustable on it. Even if it means changing the upper or lower shock mount to do it. 17.2" extended, 12.2" compressed with a 13.75-14.75" ride height

Question for those that have actually disassembled and or rebuilt both brands, QA-1 and Afco and you can throw Strange in there too if you KNOW. What exactly is the difference of the internals that makes one better or worse than the others?

To the OP 150 sound like too high of a spring rate for that car.

130 lb spring. I've considered trying 120.

You might benefit from a good double adjustable coilover. Afco seems to be a good shock. I'm running Afco sold through and re-valved by Menscer. They are the Menscer brand shock. They're probably overkill but you only live once. I really like them. I originally had Aldan. They worked OK at my power level. I've never tried any others so really no basis to compare.

I have Afco 3850's with 125 lb. Springs on my 69 camaro. They were a huge improvement over what I had.

afcos are hard to beat for the money

Your best bet is to call John Calvert Monday. He will tell you what you need. He has forgotten more than most here know.