geckonz08

Having raised the roof of the ex. port about .35 " I would like to fill the floor a similar amount.
I am mildly offput by the possibility of weld /brazing cracking the heads.
Is there a product ,sort of malleable metal similar to j b weld ,that can take the heat ??
I will be brazing the divider including preheating the heads as I can1t imagine a metallic cement staying there.Should I bite the bullet and do the same with the ex. ports ?

tx mike

cutlassefi

Spray welding seems to be the best way to go. There are some guys over on ROP that have done it with good success.

Check out the Extreme iron head post on there as well. He did alot to his C heads but hp/tq isn't where he thought it'd be. Before you invest all the time and money make sure it's right for your application.
With the cam you're getting from me, it would suggest more of a mild build. Make sure you don't stray from your plan.

Run to Rund

You can mill the exhaust side about .18" to bring up the center divider as well as taking some of the worst out of the curvature of the ports. You can make a plate like a header flange with tongues that go into the exhaust ports and raise the floor. Then you have to find or make headers for the new port positions as well as fit into the chassis. Spray welding is effective if done by an expert but it seems like you are talking about a large amount of welding, potentially.

geckonz08

Mark, not digressing from orig. plans -always intended to attempt to flow the heads a little better.Other than that just an 04B intake , 0.030 over 10/10.5 :1 ,headers.
mike

geckonz08

Brilliant tx .I have to have headers fabricated anyway(going into a D platform) so that will suit just fine
thankyou
mike

Warhead

Mill the exhaust side of the heads .180", fill the crossovers, and run a 1.625 valve with NO back cuts. Shorten the guide boss down some.
Clean up the ports, straighten them out a bit, if you want.
Any more than this is just a waste of time and cash, with no benefits from any more additional work.
The valve will out flow the port until you raise the port floor over an inch more, at the exit.
As appreciated as your efforts are, other avenues will respond oh so much better than more max effort here.
Get some 2.125 intake valves instead.
My opinion.

Jim

geckonz08

I hear you Jim. Have done all you mention to this point except the large intake valve( my valves are 2.07/1.625).On ROP there is a chap who has just used a bench flow to test this (cj455 user name ).He states the same that olds heads LOVE big valves .
tx mike