I got a BMR K-member and I don't want to spend the extra dough for spring perches. I have a set of PA Racing coilovers that I bought about 12 years ago, still new in the box. Right now I have a set of big block springs so I need to change them out.

Question 1: Are coilover springs interchangeable between manufactures, or do I have to work through PA Racing?

Question 2: What are usual spring rates for a small block Chevy? I have an iron block LSx but the weight should be almost dead nuts the same as a Gen 1 small block V8. My 4th gen with 6.0L iron block would use 315 or 325 spring rate. Not sure how much different a 3rd gen would be.

depends on the spring, measure the ID and thats what the springs are. most couilover springs are 2.5" ID. some are smaller, some are larger on one end. I would not mix and match springs side to side, but any brand springs should be fine.

Iron lsx engines are supposed to be a little lighter than a aluminum headed sbc. I would say 300 ish. but its had to guess. I had 325's up front in my 86 when i had coilovers and they seemed fine.

Yep, you're right. They are 2.5" ID. Thanks for the help. Absolutely tiny in comparison to the QA1 I have for 4th gen.

I got the box down off the shelf and I am shocked that they are 175 springs. I knew they were supposed to give me a good launch but I have to think it was a complete mistake and they sent me something for a Honda Civic or something.