To 2.02 or not to 2.02. That is the question

[VegasJen]

Hey guys! I'm back, looking for some input.

I'm building a 350/5.7 vortec, but this is for my Suburban. How is this Corvette related, you ask? Well, I'll tell you! I have a 4 bolt main block that's going in the '81 (as soon as I find a steel 1pc RM crank I can afford) so the 2 bolt block that's currently in the 81 is coming out.

That 2 bolt block is going to get donated to the Suburban. It's already .030" over and I have some 4 valve relief hyper pistons for it. I'm building this engine as a mild street/off-road engine. Only mods I'm doing is 1.6 rockers for a bit more cam effect, long tube headers and an MSD 6 box. So a very mild hotrod.

Now, the heads currently on the 2 bolt block are lightly ported iron 2.02 heads. I forget what the valve springs are exactly, but they're rated up to .480 lift, easily able to handle the stock cam with 1.6 rockers.

The 5.7 that's currently in the Suburban now has stock reman heads on it. I don't remember the stock valve size, 1.94" or 1.96", whatever size the factory had. But it has the stock springs, retainers, etc.

So the question is, with such a mild build, should I bother with the 2.02s? Or are they overkill with the lift/duration I'll be running. I am thinking about putting the 1.94" reman heads on it, but my only concern is possible spring bind with the 1.6 rockers.

FWIW, with this engine, I doubt it will ever see 5,000rpm.

What say you?

 

[BBShark]

I have a old Tahoe. If I was to rebuild the engine, I think I would keep it stock(ish). At the RPM I drive it, not sure I would see any benefit from high flow heads.

 

[mfain]

You didn't say the origin of the reman heads. If they are Vortec heads, they are lean burn and flow very well, but they require a Vortec-style intake. This is from the Jeg's website:

"America's favorite high-performance cast iron small block cylinder heads offer big power and bigger value. Chevrolet Vortec Cylinder Heads' fast burn combustion chamber and high-velocity ports combine to produce big horsepower. Vortec Heads can be mildly ported for additional performance and milled up to .040'' for increased compression ratio. The Vortec Heads come with various intake and exhaust valve sizes to complement the high-velocity port design and your performance needs. Vortec Heads outflow Bow Tie Heads right out of the box and are a 20 to 40 horsepower bolt-on increase over earlier cast iron small block heads. Vortec Heads require a Vortec-style intake manifold due to an improved manifold mounting flange and gasket design and raised intake ports. Modifying the heads to accept early intake manifolds is not recommended. Vortec Cylinder Heads fit all 1955-Present small blocks except LT1/LT4 reverse coolant flow engines and current LS1-style engines."

Pappy

 

[VegasJen]

Ya, they are the factory Vortec remans. Only thing I'm worried about is coil bind with a 1.6 rocker. Not worried so much about floating a valve. Like I said, I doubt this engine will ever see 5,000rpm. I think I would prefer using the Vortec heads over the 2.02s.