Thread: 402 heads

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Bitchin'! I've been mulling over a 331 / 347 stroker and I thought I remembered you mentioned that someone left one behind or something like that....

nope he pick that one up 289 ford with a HYD Erson hyd roller kit in it i do work on fords i not sure if i have any photos of that one just a mild one nice street runner

Originally Posted by pat mccarthy

nope he pick that one up 289 ford with a HYD Erson hyd roller kit in it i do work on fords i not sure if i have any photos of that one just a mild one nice street runner

No sweat. I've been thinking is all!

what happened to 70chevybb? He has not replied since told the 6272292 heads were not 119cc chambers. I looked up some info from other websites they are open chamber and listed anywhere from 110 cc to 111cc. Intake and exhaust are 2.06/1.72.

i built many of them heads a cc them there abit more then 110 stock valves are 2.06/1.72 many times they do not say that size

I'm still here. I had an old friend give me a 454 and am now going to switch from the 402. I cc'd the 292 heads and sthay are 119cc the best I can tell. The 454 heads are 110 cc which will give me the copression ratio I need. I am still a ways from needing a running engine so It will be a slow build. I am rebuilding the cab of my truck right now. I have the frame fully restored. I will post some pics soon.

Thanks, Wes

Originally Posted by 70chevybb

I'm still here. I had an old friend give me a 454 and am now going to switch from the 402. I cc'd the 292 heads and sthay are 119cc the best I can tell. The 454 heads are 110 cc which will give me the copression ratio I need. I am still a ways from needing a running engine so It will be a slow build. I am rebuilding the cab of my truck right now. I have the frame fully restored. I will post some pics soon.

Thanks, Wes

sure like to know how you cc a head from GM there is no way it.s 119 ? at best 116cc . i used this head for over 20 years .the ones i built that were 292 casting i had on my mill and cut to a cc chamber i wanted .they never started at 119

I have used the 241,820, and 292 casting heads. All are similar chamber shape ( xtra exhaust shrouding) and all that I have measured are as Pat has stated, 113cc. I have the 292 casting on a 30 over 402. I pocket ported them and added the larger 1.88 exhaust valves. (11/32 back cut/ stainless). They work real well with the current set up. Next week i am pulling them to add different springs as I am switching out the flat tappet cam in favor of Howards pn 12315-10 camshaft. (227/227/.555/.555 110). Its difficult to make compression out of these 402s. I am going to cut .015 off the heads and use the Mr. Gasket .019 head gasket. It should put me about 9.2 to 1 with the KB160 and i'm .020 in the hole. This compression should be fine for this cam. Good luck with your build...

I have given up on the 402. I have taken the 454 to the machine shop. I will be going with the 781 heads and am having 2.19 and 1.88 vales cut in. The speed pro pistons have a .210 dome and will give me 9.77 to 1. My crank will be polished and will use pat's recommendation for a roller cam and rockers. It will be a slow build as I have alot of truck work to do.

Wes

It looks as my block will need to be bored.060. I will now have a final comp ratio of 10 to 1. Is still a good sreetable ratio or should I loer it?

Wes

yep if you run good gas

Very nice work Pat. but I expected nothing less!

I found a set of 049 heads that have had hard seats on both intake and exhaust. They were upgraded to the 2.19 and 1.88.
I can pick them up for 300.00. Are the 049's as good as the 292's or 781's .

Wes

should be no need to seat the intake side of the head when cutting it to a 2.190 intake are you sure they have seats on the intake side ? the 049 and 781 are about the same head

I am going to go look at them friday. The person said they had seats put in. He said something about having them interlocked because they touch in the middle. He claims that he drove less than 1000 miles on the heads before he pulled them and switched to rectangled port heads. He also told me the name of the local machine shop that did the work so I could verify most of his info. Are they worth 300.00 ??? Is it a big issue to have hard intake seats??

Thanks, Wes