Stock Intake

[Bill Gordon]

I'm planning on pulling my motor this year and installing a 331. I'm keeping the stock lower intake (will have it ported) because of the Kenne Bell blower. Will any of the aftermarket heads work with the stock lower? I read that the Ford Racing GT40X will not. Not sure if any others will. Thanks.

 

[tonydalrymple]

Do you mean a stock Mustang lower or a "stock" Explorer lower? The stock Mustang lower will take a huge amount of porting to flow a decent amount of air. It takes welding up the short side turn radius side of both #1 & #5 runners\ports since you will bust through the factory casting hogging them out (been there; done that). N\A, doing the work myself; it was worth about 240rwhp&300rwtq on a 306(stock long block otherwise than the self ported intake). If we're talking about a stock Explorer lower; the same applies as above. The difference is 300rwhp\310rwtq on the very same 306 with a performance cam & AFR165 heads. Pressurized; you'll see quite a bit more & still enjoy having massive torque at low rpm IMHO....

 

[rbohm]

on the intake side, the stock lower will work with any of the aftermarket heads, unless they require a special intake and none do that i know of. you can also use any of the GT40 intakes as well, you just have to use both halves due to the changes in the port locations where the two halves come together.

 

[Bill Gordon]

Tony, the stock Mustang lower. I have to keep it if I want to keep the Kenne Bell blower (which I do). The KB blower will only work with the stock lower intake. Not too concerned because I will have it ported. I was worried about the heads. The Ford Racing 306 CI long block I was first looking at has the GT40x aluminum heads that will not work with the stock Mustang lower (according to the Ford Racing website).
rbohm, if that's the case then life will be good...I'd like to run a set of Trick Flows or AFR's and a cam to match the blower in the 331.

 

[89oem]

some folks have issues with the GT40x alum heads / intake matching because the ports are higher, here is a really good thread with specifics on the issue, and if you want someone to port your lower tmoss on that thread is the intake porting guru, you may know all this just throwing it out there...

http://forums.corral.net/forums/5-0-5-8-engine-tech/1570250-intake-question-fitment-issue.html

 

[Bill Gordon]

89oem, yea that's what I saw on the Ford Racing site, the GT40x ports being too high. I am going to look at other heads that will work with the stock Mustang lower, just not sure which ones will work.
Thanks for the link, a lot of good info there.

 

[Bill Gordon]

Seems like after reading that post, only the GT 40x heads have that issue with the tall ports. Looks like the GT 40P and other aftermarket heads will work fine. Looks like the guy in that post was trying to use a Cobra lower and GT 40x heads. The Cobra lower and stock Mustang lower must have identical port locations.

 

[89oem]

seems like the strong favorite on the boards is trickflow 170's as you posted originally , afr has their fans too.