Bigger valves in low performance heads

[Dave N]

Is it possible to punch out the 379 heads to the larger 1147 heads valve size I believe it would be 1.94,1.66 on the 379 heads to 2.06, 1.72 for the 1147 heads is it possible and doable and has anybody tried it.
Thanks Dave N.
Blue 63 Conv.
Green 60 Hdtp.

[fatride]

Is it possible to punch out the 379 heads to the larger 1147 heads valve size I believe it would be 1.94,1.66 on the 379 heads to 2.06, 1.72 for the 1147 heads is it possible and doable and has anybody tried it.
Thanks Dave N.
Blue 63 Conv.
Green 60 Hdtp.

Yes it is doable and I have a pair in my garage right now. There is other work to be done to take advantage of the bigger valves but that can be done on your bench at home with the right tools.

[Dave N]

what other suggestions do you have I have a late 60 Impala and I'm trying to replicate the 350hp motor from late in the year without incuring the larger cost of 1147 heads I have all the rest of the tripower stuff and am going with the stock solid lifter cam and 2 1/2 inch manifolds. Thanks in advance
Dave N.
Blue 63 Impala Conv.
Green 60 hdtp.

[tripower]

Dave, You would need to port the heads. I think the 3X2 HP for 1960 was 335 HP and the 4-bbl was 340 HP. I am not sure but I think the 4-bbl manifold for the 340 would have been the aluminum 3753748.
Here are the suffix codes.

FJ 1960-61 Pass. Car 340HP 348 V8 4 bbl., manual trans., High perf. solid cam

FE 1960 Pass. Car 335HP 348 V8 3-2 bbls, manual trans and High perf. solid cam

[CDNpontiac409guy]

JMHO... but I think a proper modern cam profile would be more effective than changing valve size in the wrong ( "wrong" for a 350 horse ) heads. That stock cam is somewhat pitiful.:yawn:

As for putting the 2.06" / 1.72" valves in the 379 heads ( or 333's )... it's done daily.:deal

[tripower]

Good advise Aubrey...:clap