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My C5 front setup is lacking the front mono-leaf (due to my own foolishness, unfortunately, I did have it). I'm trying to consider my reasonable/cost-efficient options, and not having a lot of luck out there.

1.) Just get another mono-leaf and install - currently looking at around $150 - almost don't want to do this out of shame for destroying my other one.
2.) Coilovers - C5-spec ones out there start at around $1000. I "could" - but as it's not a C5 it wouldn't be the benefit the $ is suggesting, and I'd rather not spend that kind of money on them.
3.) cheap/er coilovers w/bell cranks - Could probably make this option work for around $100, and I like the thought of them. Placement/positioning might be a pain, as my cabin wall is almost directly in line with the center of the A-arms, making the ideal mounting not feasible. I've seen all manner of alternative mounts, but I'd need to put in some significant time to understand how to make them function properly.
4.) cheap coilovers w/fab to fit - I haven't looked at if I can modify a set to function in the C5 location. Most appear to be significantly shorter, and on many of the options out there a travel isn't even listed.

I've done some light searching on the forums for options and not really come up with what I'm looking for, so thought I'd see if someone had it off-hand.

Jon

Preface this with: I don't know what you're building, and am assuming it'll be "locost weight."

Coil-overs are a mixed blessing, likely fairly cheap from "the yards", but may be completely inappropriate. You can answer the question yourself: how much weight will be on each corner of your project car when it's done, and how does that compare to the weight they saw on the OEM car? Springs are only half the story - the easy part - because they can be swapped out for appropriate units (assuming they're available aftermarket). The real problem is the shocks, specifically, the valving. If a shock on your project car will see 1/3 the weight it saw on the donor car, it's going to be way too stiff, bad for handling and very uncomfortable. There are games that can be played with the installation ratio regarding the springs, geometrically reducing their rate, but the shocks, unless adjustable, are going to be an issue. It's why most (all?) Locost builders go with aftermarket springs and shocks.

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Key insights on the car:
1.) Intended more to enjoy the process and learnings than the outcome. I expect it will be heavier, uglier, rougher/rawer, with a slew of mistakes that had to be corrected or "lived with". And that's ok. IE - using the corvette frame sections instead of making my own brackets cost me significant footbox room - but I'm not correcting that. I DID, however, add a few inches to the wheelbase - and I'm on the fence as to if I would do that next time or move the cooling package to the front.
2.) LS4/Impala front subframe/drivetrain including struts moved to MR/RR configuration, C5 front cradle (including frame members), main chassis members made of 1.5" .120 square stock, intend to build fiberglass body. If I come in under 2500lbs I'll be pretty excited/happy, and most of that will be on the rears. It's in raw/rough near-roller status (it would roll but the front would be near bottomed out without anything holding up the front). 107" wheelbase.


On me:
I've been sitting on most of the parts needed to get going for almost 7 years without putting anything together, and got tired of constantly changing my mind on big parts/thoughts/ideas - so decided to just build something, and then use the lessons learned to make more. So far I've REALLY enjoyed just sticking things together, blocking out and imagining where it is going to go and letting that guide me.

At this point something that would hold the car up is the "acceptable" - so any of the options that I could make work are fine. I imagine the front end will be quite light - other than maybe the battery (and probably not), I intend to leave the LS4 equipment as it sits (so cooling package, etc is in the rear). So front won't be holding up an LS1 and cooling package as it would be stock, but will still have to contend with most of the other things (lights/bodywork/etc).

Looking at the "ebay"/amazon ATV/motorcycle coilovers, I can find a close length, and they claim 660lbs at <200lb/in spring - which seems like it would be pretty ball park - but they have half the stroke that my suspension can handle. Which seems I could adjust for with a roughly 2:1 bell crank if I can make the setup make sense to my head. But I figured someone has already agonized over this and might have the easy answer. With suspension (as with most things), consider me to know just enough to not sound like a moron in casual, and basically what it all does and how it goes together... but the fine details are beyond me. For instance, I don't even know if I need or want the full 5" of travel - maybe half of that is plenty....

The front shocks on a C5 aren't really Corvette specific if you are willing to modify the top pin mount. The lower uses a common cross pin you can find online to fit any coil over with a spherical joint. The rears are Corvette specific because of the lower C shaped mount.

The top mount on the front can be a simple C shaped piece with a bolt that goes where the original pin mount went.

I have a very used set of Bilstein coil over shocks for a C5 you can have for the cost of shipping. Not only are they used, but they were shortened by the person I bought them for. When I say used, I bought them used in 2007/8 timeframe. I ran them on the track for about 12 years before replacing. I would suggest they need a rebuild, but that would allow you to have them revalved for your wheel rates. That might get you close to the $1000 you mentioned before, so I don't know if that helps. But, if you want them, shoot me a note.

Ken

Front of my car uses 99 Yamaha r6 rear shocks. They work PERFECTLY. We calculated the spring rates at a particular angle to be a good match for my 1240lb car and I'm still amazed at how well they work for the application.