Question For The Head Porting Gurus

[osprey2020]

Hi
I am planning on doing some porting and polishing and gasket matching on my GT40-P’s. I picked up the Fel-Pro gasket set #MS 93334. The intake gaskets in this set are supposed to be the same dimensions of Fel-Pro gasket 1250. When I went to line up the gasket to make the marks to gasket match, the gasket was too big (my intake ports were bigger than the gasket). I am already lost --- what do I do from here, trim the gasket, get a different size gasket, do nothing, etc -- My upper is an Explorer and the ports are smaller than the gasket, but not by much.
Thanks once again for all the help and to all that reply.

 

[Michael Yount]

There's simply not a whole lot to be gained from this type of port matching, and by opening things up too much, you can have detrimental results. I'd leave it alone if I were you. The P's and intake were designed to work together (they came that way on the Explorer) - I'd just carefully assemble and enjoy your upgrade.

 

[tmoss]

The gasket in that set is not a true 1250 gasket (1.2"x2.0") as it has dimesions of 1.15"x1.90". I put that gasket on my GT40P heads and they matched perfectly. Just rim them some and use them. CAUTION - unless your going to use a cam that will benefit from the port work your talking about, you may hurt things more than help. My stock cam valve events came out VERY close to the Crower 15510 cam except mine has a little more duration and when I asked a well known custom cam supplier if he thought doing a LITTLE port work on the exhaust was a good idea he said no, as the cam specs at a 109 ICL would work best with the heads bone stock. Also, be aware that the P head flows a lot early compared to the GT40 but flow tops out for all practical purposes at .400" lift, so running a cam with more lift will net you little power - it takes duration to make a difference with these heads - not lift, and you can go to far there also. Get some expert advice!

 

[thumper460]

If you use the 1250 on the P's you will find the cross section is pretty much right on... the height will be a little short!! just radious the lip for a smooth transition from intake to heads... and note the differance in the intake as well!! there are no HUGE gains to be made matching them... but there is some!! Dont get exoit and go crazy!! the P's will make good power for you/... cool??

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

Thumper