I have a set of 462 heads with 1.94 and 1.5 valves. The heads are at the shop right now and I was asked if I wanted to machine them out to 2.02 intake and 1.6 ex. or rebuild them as they are.

Do you think it will mean more to me saying that's what they are or whether I will actually notice it driving. I'll do it if it's going to be a nice difference.

Ryan

That will depend on the rest of the engine, such as cam, intake, carb etc. I'm thinking that it would even result in a loss of low-end torque in a stock engine. Bigger is not always better.

If you do go 202-1.6 you will need bowl blending(porting) otherwise you just wasted good money! you will loose power if you dont blend the bowls!

But the good news with larger valves is that you're on virgin metal, so the valves aren't sunk into the head. That, in turn, translates into better valve train geometry or better clearance between valve retainer and rocker arm.

Might want to look into hardened exhaust seat inserts, though.

And you also need to plunge cut each chamber around both valves like stock big valve heads are. OR you may not flow quite as good as stock medium vlave heads due to valve head shrouding by the close chamber walls.

This is why most big valve double-hump heads cc right at 66 to 66.+ cc's vs 64 cc's for the medium valve heads!!

pdq67

If this is not a "numbers" build and you're looking for some more power from a mild build, get some Vortec's or an aftermarket "S/R" head ?

I agree.....camel humps are really not worth putting $$ into unless you're doing a numbers matching resto.

I just had a pair of 194's ported polished and bowels blended for my 350 and they flow very well, like 256 cfm at .500 in 28.0 H20.......I think it was well worth it.:thumbsup:

The 1.94 intakes are just fine for stock or mildly built street engines. They actually help better low end torque which is important for cars with high rear end ratios (low numerically). I would recommend upgrading the exhaust valves though. The 1.6 exhaust valves promote better scavenging which helps makes way for the incoming fresh fuel/air charge.

Randy is right!! Less pumping losses with 1.6" exhaust valves!!

It's basically free hp..

pdq67