454 head question

Hi,
I am building a 56 chevy with a 454. I was going to build the engine to the Edelbrock total performance performer RPM package. They say this will produce 540 HP. I then decided that this is more than I want for a street only engine. My quesiton is, I have the original heads with casting number 336781 on them and they are the oval port heads with the 2.06 valves. Will thes work and lower the horsepower a bit over the edelbrock aluminum heads they suggest? How much horsepower can I expect and what should I do to the heads to make them work if I decide to go with them? Thank you for the information in advance. Docjim

781s are great heads, would be really nice if you put 2.19/1.88s in em. youll be down some horsepower, Im gonna guess 30-40 HP compared to the RPM headsat the most, but chances are that loss will only be in the upper rpm range anyway. John

Those oval port head's will work very well with your motor , they produce a lot of low end torque . If you can afford it though the Edelbrock's are awesome plus your putting your Big -Block on a big weight loss program. Less weight is a big factor with me!:D

Docjim, the 781's are great heads, even as they are with that valve size. If you're not going to race it, you wont notice or feel any difference between those valves and 2.19/1.88's or larger. And in the same vein, if you're not racing, the weight loss will not make a difference...but you'll save a lot of money!! (Aluminum is nice, but pricey) The only concern with those heads is the rather large combustion chamber, unless you use a domed piston, your C/R is going to be low....with the stock pistons, it was way down, less than 8.0/1. A big dome piston with stock chamber sizes might get you up around 9.25 to one, not bad. I dont know what you're looking for. John

Keith Black lists a piston just for that combo. Not a big dome and gets the compression back up to reasonable street use. Available with either std 5/64 rings or the 1/16 rings. KB257 is the std ring set no.