Help with LQ4 swap in 91 Z71 RCSB

[Gemini]

Yeah the truck intake will work with any cathedral port heads.

I did some math to figure out exactly what your compression would be.

Bore:4.000

Stroke:3.622

Head Gasket Bore Diameter:4.03

Compressed Head Gasket Thickness:0.051

Combustion Chamber:64cc (243 heads)

Piston Dome Volume:-6.7cc

Piston Deck Clearance:-0.010

Compression: 10.4:1

I couldn't fine a concrete answer on deck clearance for the LQ4. Some people said -0.007 and some said -0.013. So I went with -0.010 just to get an idea.

Your Compression may vary a little depending on which gaskets you use and your deck clearance. But worst case you will still be above 10:1.

I'm not sure as far as your piston to valve clearance on the cam I would assume it's safe but that's a complete guess. Your max lift isn't as much of a concern as the lift at and before 5-15 degrees TDC. I would give a reputable cam manufacturer or a performance shop a call and ask for some advice there.