I've got a C5 Z06 that I was going to do the A & A kit with my LS6. The more I think about it, I think I'd rather go bigger motor and just stay N/A.

I know guys do a 416 LS3 build that performs very well, I also wonder about the LS7's at 440 or even the LSX block builds.

Question is, if you were going to stay N/A but wanted to make big power in a C5 Z06, what would you all go with?

Looking for ideas/recommendations.

Car is mainly a street car - very little track use, if any.

Thanks!

 

What do you consider big power?

 

It depends on the technology of the engine you want to use--cubic inches aren't the only factor involved. A 416 LS3 will perform great but, will still produce less power than a SBE Gen V LT. Your maintenance tolerance, your choice on hydraulic vs solid roller camshaft, fuel, etc., etc., will make more of a determination about what your combination will likely entail. I, personally, wouldn't touch an iron block in any modern vehicle, but that is a personal preference. A 440ci LS7 and a 440ci LT1 will have very different power curves.

If I wanted to keep it simple and have the least amount of money into machining, I'd just get a 416 LS3 with the new BTR Canted Valve (rec port) heads that are ported and use OEM LT1 valves, a custom camshaft around 23X/24X, 112LSA, .640-.650 lift and a comfortable ramp rate for the springs you choose, with a nice high-ram style intake manifold, 102/103mm throttle body and 93 or E85 fuel (the latter being far superior). That'll likely get you into the low 600whp range. Unless you're shooting for 800+whp N/A, I wouldn't look at the 440ci LS7 or LT1 stuff. Although these days, 440ci LT1 engines are routinely pumping out over 800whp and will likely crest 900whp soon.

More directly to your question, if I were shooting for big power, I would go with a Gen V LT1 and not look back.

 

Check summit racing, I think they sell a 427 iron LSX block. You can probably build it to your own specs. 24x reluctor wheel, aluminum heads, fast intake, etc…. Custom rotating assembly.

 

427 is the magic number, for me.

 

Lots of ways to crack this egg.

Define the power you seek, and how you want it. As well as how much you want to spend. Is this a 15k basic? Or a $40k monster?

Your best bet overall is going to be to buy a car with all this already done and save 20k right off the bat unless you're married to the current car.

So what's the goal:
- Chopp
- low 10 second ET
- stroker with piston skirts which nearly come out of the sleeve
- enough to require drag radials at all times
- or something more specific and niche

I vote for burnouts and ice cream.

What is your commitment level to the C5 in question and what's already been done to it?

 

Iron block for an NA engine in a C5?

Just get one of these.

 

Sell ya my C5-R block for cheap! Special deal. LOL

 

I went with a 454: 4.185 bore, 4.125 stroke.
There are a couple shops make 486s now, using a 4.25" crank.
But if you're going with forced induction, 427 or 441 might better as they will allow slightly thicker sleeves.