Cobra gt40 head Question??

[scottmrit]

My question is can i put 1.94 and 1.60 valves in gt40 heads and not have to flycut my pistons. I will clay the pistons and check the ptv, but just wanted to know if i will have problems right off the batt.
The heads have at least one bent valve and i am going to put new guides in it and also do a 3 angle valve job. The motor has the crane 2031 cam and spring kit in it right now.

 

[scottmrit]

Oh yeah the head have been ported and polished, runners matched to felpro 1250 and 1415 gaskets. Also have been pocket ported so should i just buy stock valves or go bigger

 

[thumper460]

The 1.94- 1.90- 2.02 big valve works in an aftermarket piston, as FORD cuts their Notches for the 1.85/ 1.55 valve size!! It isnt the depth of the pocket.. it is the outside radius of the pocket!! We have had issues with a 1.90 Valve, SOOOoooo.... IF you go that big the piston will more than likely need notching , or at least the piston notch "layed Back" to fit the Valve size... Cool??

Just a thought!! Keep the stock valve size ( for P/V issues) and up grade them to the undercut stem stainless valves.. you will increase the low to mid lift as well as the top end!! The shrouding in the chambers and the cylinders will be less than the larger valves and you will fly when it is all pulled together with a good performance valve job !! Just a thought... some times "bigger isnt better" Cool??

Just me...........................................

Thumper

PS.. and if you have the heads Ported and Polished... you will be amazed!! cool??
Tpr

 

[scottmrit]

What valves do you recomend for the heads thumper

 

[thumper460]

Any good quality!! You dont need ass kick'n, high dollar 8000 rpm quality!! Just make sure you have the "undercut stems", the machine shop could suggest some.. for YOUR application, Mine are $180.00 and I will ship them to ya free.. just a thought.

Just me.......................................

Thumper