[b]454 oval port heads[/b]

[stickshift]

On my 1972 454 engine that I am building, I am using the stock oval port heads. We are putting bigger valves in them. My question is, should I have them ported and polished, or should I just wait later and get a set of after market heads? We are going with dome forged pistons to get my compression to 10.5.1. The guy at the shop said that if I decide to get after market heads later, I would have to change my pistons because it would make my compression too high. Would I really have to change pistons if I decide to upgrade my heads later?

[mrj52]

In My opinion I would put the 2.19 intakes and 1.88 exhaust in those heads. Pocket port under the valve seats and straighten as much as possable the exhaust throat short side radii. Do not polish the ports. The 1.88 valves greatly help in improving the above mentioned short side. Your 72 heads are about 114 cc, a mild open chamber piston {hyperutect} will put U at 10.00 to one. I would not go higher on a big block on iron heads ie detontation. If you go with open chamber pistons and get some after market heads you will have stay with open chamber design. Okay, If you are going with the TRW forgings in a pop-up design you could use the 70 LS6 piston { closed chamber design } in your open chamber heads for 10.00 to 1 OR you use the 71 LS6 piston { so called open chamber piston really a closed chamber design } for 9.00 to 1. This piston can be used in 110 cc design head like Edelbrock for 10.00 to 1. if you changed the heads later. Now that you eyes have glazed over I hope you are not confused. Ive been down this path so ask away again. TIM

[72 LS5]

I'm with Tim - the compression seems high for iron heads.

 

Most aftermarket aluminum heads are 110cc since you can run a higher c/r with aluminum. If you swap heads later, you won't have to touch your bottom end.

 

OR, Rather than investing in modifying your iron heads with port work and bigger valves, I suggest springing for the aftermarket heads now - it will only be a few hundred more. You will have brand new heads that flow better and save about 70 lbs off the nose of your car!