[ITSBACK]

I have a 67 428 HO for my 67 GTO and will be going with an SD port job and Old Faithfull cam when all said and done. The 670 heads are rebuilt stock at the moment and the block is .030. I will be using a stock intake, Cliff Quadrajet, headers, 3" exhaust, 4 speed, 390 rear. As you know this is not the cheap way out but well worth it. There is a guy selling a Ram Air IV 041 cam and lifters here. Can I use my stock heads and motor with that cam while I save for the final 428? Will I be able to build it with the same pistons? Will it be OK for the street? Should I just build a 400 with all the parts until I can afford the 428 build? The bottom line is that using what I have will get me driving sooner until I can save the cash for the final motor. Input would be great.
Thank You,
Bill

[bobzdar]

Imo, that's one step too big for unported d-port heads regardless whether it's a 400, 428, or 455. Try a 744, crower 60916 or similar. With mild porting, the raiv cam would be good. With those gears, it would be fine on the street.
Same pistons won't work in a 400 and 428 due to different pin heights being required.

[ITSBACK]

As far as pistons, I meant if I used the cam in the 428 and then later did the cam and head work so I would not have to do the bottom end over.

[ITSBACK]

Trying to avoid any port work now, just going stock heads for now to save money for later.

[lust4speed]

ITSBACK, are you going to do the bottom end build on the 428 up front? The reason I'm asking is I've seen too many hidden problems in "good" stock engines, and there's many things that can be bad or go bad if not replaced up front. If you don't do the bottom end, then you are dealing with stock rods, stock rod bolts, and cast pistons. Many of these old engines had detonation problems that were ignored, and will have broken rings and hammered bearings.

You can do a search and see how many stock Pontiac 2-piece valves have come apart when a new cam and springs were installed. No way of telling if the valves are just below the failure threshold. They might last for another 50,000 miles with the original small cam and weak springs, but break very soon when the stress is increased. I don't have a problem running an old engine in its 'as is" condition and just driving it easy. The danger is beefing up only a few areas and hoping the remaining parts will continue to live.

I've got a set of 670's that Dave did many years ago and they are great. They are opened up to 83cc chambers and we are running a dished piston in the 4.25" stroked 428 to keep on good terms with our local 91 octane gas. Get Dave's recommendation on what he would currently recommend on chamber work and piston dishing before turning your machine shop loose on the block.

[ITSBACK]

The motor is apart and machined already. I have a set of Eagle H-beams to use and will be going with forged pistons which of course I cannot buy until I know the cc of the heads. I WILL be using Daves head and cam package. The heads I will be sending to Dave are currently a fresh rebuild to stock spec. I am just trying to see if I can build a bottom end that will meet the needs for Dave, but use that bottom end with the current heads and a good cam that will run until I save my money and do a winter SD makover and yank the heads and cam and for Daves stuff. If I do that I wiull be driving my car a few $$$$ sooner. My motor was 376hp stock so I know with a good cam I will have at least that to 400hp which is not the same as Daves 500-525 but its better than looking at it in the garage waiting longer. For that matter am I better off just building a different motor for now say a 400 or another 428 or 455?

[bobzdar]

Then the answer should be yes, if you're planning to use the same heads, the pistons should work before and after porting. You may want to have the heads shaved a tad if the cam is going to be bigger or if the sd port job opens up the chambers a little to get optimal performance but it probably would be negligable performance wise. I think the raiv cam will work well, it'll just be a tad bigger than optimal.

[ITSBACK]

I guess the pistons would be the same anyway as my compression will not change since I am using the same heads they will just be ported for Daves cam and valve work. I would have to get the heads cc'd then I guess for the correct piston and speak with Dave about the compression I need and take it from there. For that matter I can use my 750dp and grab an rpm manifold until I do the SD package. Thanks for the input.

[joeq]

Had a RA4 cam in a .060 428, mildly ported "62s", RA4 intake and Qjet.The engine would ildle@ 600rpms, and relatively smooth. Pulled about 15" of vacume (if I remember right).

[ITSBACK]

Thanks for the input. Spoke with Richie Hoffman a little while ago. He gave me some real good options. Just going to bring what I have to him and he will work it out so I can do what I want. Great guy.