what is best?

[tkeinia]

i am putting together a motor, maybe 331, i have a trickflow upper and lower intake, xcam or tfs stage 1 cam, not sure which to use,

main question should i use stock gt40 heads or some ported 69 or 70 351 windsor heads.

i plan on eventually puting on a powerstroke disel turbo i have but not at first.

 

[tkeinia]

i forgot, i can get the gt40s for 100 and 351s for 200

 

[beejay31000]

not bad pricing. i would get the gt40's and port them

 

[Mustangcwo]

Given the choice between the two alternatives, I would get the GT40 heads. If you intend to increase flow through a 331, you'll need ported GT40 heads. Make certain that the heads are a true GT40 and not GT40(P). Here is how you can tell:

On the face (area were the brackets go) there will be 3 vert. lines on the inside (intake side of head) corner of the head these are part of the casting marks gt40(non-P) heads the P heads have 2 lines, also there is a GT cast into one of the far corners (ouside of vavle cover area) the other side just has numbers, and one cast GT in the oil vally area.

Twisted Wedge Heads is still the best alternative, but the cost is high.

 

[tkeinia]

thanks, i was leaning toward teh gt40s but i wanted to get some opinions.

 

[IgottaV8]

I have ported GT40 heads on mine (as far as I know) And I think that they are the best option that you can go with.

 

[tkeinia]

thanks

 

[orange395w]

The 69 heads are like 64cc if my memory serves me correctly. Compression ratio is something to think about as well. The compression would be lower with the 351w heads, but the valves may be bigger. Either way both will choke a 331, but like mentioned the GT40's are probably your best choice unlees you need lower compression for a blower or turbo.

 

[tkeinia]

i plan on runing a turbo soon, the gt40s are stock and the 351 are ported adn polished wiht a 5angle valve job, also are studed for pedistal rockers i think.

100.00 for teh gt40s
200 for the 351

 

[Foxman]

pedestal rockers don't use studs....

 

[wickedstangs]

pedestal rockers don't use studs....

Why? Stud are the way to go fully adjustable.. More Power, higher revs...

 

[Foxman]

I thought pedestal mount rockers just bolt on not studs...

 

[Foxman]

 

[Foxman]

 

[wickedstangs]

yes you are correct the first picture is Ped mount and the second is fully adjustable... There is only so much you can do with the Ped mount rocker arms..

Pedestal mount are more for stock applications where decking wasn't involved or big profile cams. Easy to install as long as you check the geometry. Never had them make noise once I installed them.

Stud are better for adjusting to changes in the engine. Almost always require readjusting once the engine is ran. Now with poly locks on the stud mounted rockers is a much better way to go.