Hi. I had a mechanic put new struts on my 86 iroc,And it did improve the bumpy ride, But He told me that i should get some "bigger springs" installed as well. When i asked why, He said "because of the big block 350 engine I have in it now, being heavier than the original 305" tpi engine...My car does still hit a bit hard at times.Even with the brand new struts. But from what i have read on these forums,These cars normally do ride rough and hit hard anyway. My question is...Is he right? Is there a certain set of "Bigger coil springs" i should be using now that i have a big block engine? Im not looking to raise or lower the car or anything,But if the springs im using(stock) are too weak,I want to correct it. Does anyone have any input or recommendations? I have never shopped around for coil springs,and I have NO idea what to look for. Thanks for any help.

 

Im confused..Big Block 350?

 

yeah. That was what he called it. Its just a chevy 350 engine.

 

The difference in weight of a 305 and 350 will not make enough difference to change springs. From my experience though most new sets of springs ive bought would be between 1-2 in taller than my oem springs so maybe get new front and rear for it, cant hurt.

 

The only difference is the bore and crank. Maybe 10 pounds if that... The guy is retarded..

 

okay. Thanks.I appreciate it. That answers my question.Saved me some cash.

 

I shouldn't have of called your mechanic retarded. Maybe there was come confusion in what he said and meant to say.. ANY mechanic should know there is no outside difference. In fact...........................

All Chevrolet's V8s, from the big blocks to today's LS7 and LS9, evolved from the 265/283 small block family. Of the three engines in this family, two of them, the 265 and the 283, have gone down in automotive history. The first of this family was the 265, introduced in 1955. The 265 had a 3.75 bore. The stroke of the 265 was 3.00, like the 283. The 283, famous for being one of the first engines to make 1 hp per cubic inch, is also famous for being the evolutionary stepping stone that would later give rise to small blocks and to the "W" blocks, ultimately culminating in the Chevrolet big blocks. The last of this family was the 307, which was a stroked 283 with a medium journal.

So, maybe you do need the correct springs??? You had the 305 before or a v6 or what?

 

yeah,im thinking there may have been some confusion in what he was trying to say as well. My car has was pieced together from 2 other donor cars.(RS and a z28) from what i was told. And he said that my front springs were for a v6 engine, And that i should get bigger springs so that i dont wear out my new struts.(The gauge or thickness doesnt look thick enouph) So, im thinking the springs came from a donor car that had a v6 in it? And if I do need to upgrade,What do i look for? I/m trying to learn little by little. Are there v6 springs and v8 springs?? Thanks for the info. I love to read up on this stuff.

 

I'm far from an expert on this, but this is messed up. You need to match the springs and struts/shocks. "Bigger springs" does not mean anything. V8 Thirdgens came with many different spring ratings, Ie. different wire diameter, spacing(number of coils), spring rates, ride heights etc. Example of variables: http://www.moogproblemsolver.com/moo...rings_Spec.pdf
All GM springs have tags on them that can identify what you have if interested in searching for the lists.
There are also after-market lowering springs available where the spring rate varies at different heights.

Depending on what struts/shocks you have now, you would probably be ok with MOOG replacements for IROC, Z28, or RS/F41 springs. I have no idea what the part numbers are off hand but searching the subject here should come up with some suggestions. Otherwise you could go with after-market lowering springs, but there are things to look out for when going that route as well (Ie. out of range and bottoming out = after-market strut mounts etc.). Researching this site will give you more information from different people than I can relate off hand.

IMO, your mechanic was right on wearing the struts out with the wrong springs. Drag racers sometime use V6 springs with a V8 but the struts used in those cases are different.

BTW, you should also replace the strut mounts when you replace the struts.

If you want to wait around for someone to tell what springs to get, then I'd recommend posting what struts you have on the car now.