After racing this weekend, I've decided to trade in my 6x heads for a set of aluminum Edelbrock Performer RPM heads. I have a 1973 455 block, bored .060, ZL2359f Pistons , forged crank, 6x heads, Edelbrock performer rpm intake, and a Holley Ultra Street Avenger at 770 CFM. My 60902LK cam is by Lunati. Compression ratio is rather low right. Runs fine on 91 Octane.My goal is to get better flow and heat dissipation from the aluminum heads. I know that I will need new headers to fit the upgraded exhaust ports. I am looking for advice on what I may need to do.Roller rockers? If so, which ones?Bare or complete heads?Advice from those who have done this before?
You might consider the d-port heads from Edelbrock so you don't need to switch headers, they are designed for the street as opposed to the RPM's which were designed more for racing. Summit sells them assembled for about $2200/pair. I have a set ported by Butlers on my 400 but it hasn't been run yet.Steve
A little help... 'cause we don't all have to learn the hard way!
I think the Edelbrock or the Kauffman D port heads would work great, and your headers should fit. You can also get different size combustion chambers to tailor the compression ratio. I am running the Kauffman D ports, ported to 325 cfm and I am running Scorpion roller rocker.
i agree on the d ports because your cam does not need more flow than that.the d port, round port and kaufman can all be ported to 320 intake.i like to buy bare heads but for your app, assembled is finei would remove intake valves and have them back cut.CARB - I would install the optional white secondary spring so the secondaries open sooner. i would likely go up 1 or 2 jet sizes because these carbs are jetted lean. if you have a slight hesitation right above idle when accelerating from a stop jetting richer might help.
Thank you for the replies! I'm going with a 605719 complete head to leave some room for upping the lower end later. Now I need to find ram air 4 oval port style headers!