Does anyone know about the stock heads on these late model 351's? Won't the GT40's flow better? If so, is it enough to justify swapping them onto this motor? I plan to port the crap out of the GT40's the best I can.
And I do plan to take this thing to a dyno day somewhere to see what it'll do.
Heres a old head flow chart. From what I remember the newer 351 truck heads have the smaller 302 valves not the ones listed in this chart like the early heads. So yes the GT40's will flow better than the stock 351 heads
P41538 Image Large Photo
Also if I remember right all 351's have the 28oz balance....302's had the same until 1982 when they switched to the 50oz balance on the 302's.
The TF stage 2 cam has 542", .563". Probably not enough clearance....you would def have to check P/V with that much lift on stock valve releif pistons.
Just for an Idea what Saleen did starting in 1994. He used a Lightening shortblock and flycut the pistons for a bigger cam. I don't know the cam spec's....but have heard it's like a T/F/stage 2 cam. (I am hoping to get a stock cam to check it for spec's. #77 had a aftermarket cam when I bought it and #58 is all stock with 54k mi and I don't want to take it apart it runs fine!)
So he flycut the pistons, cam, edlbrock alum heads, 65mmTB, mass air, roller rockers, Explorer intake with the upper cut and a section added, then they are extrude honed, shorty headers, 2 1/2" cats and a
Borla cat back and a new computer I have heard they are out of a Bronco or Van with a 351 and I think he put's a tune on it.....I have never pulled #58's out to check, #77 had no ford computer it had an old DFI system when I bought it I have since upgraded it.
They were rated at 371hp 422ft lbs, 172mph. With a
Vortech and 8lbs the torque went up to around 480ft lbs and the HP to 480 also. In 1996 he put T/F heads and a different tune and the N/A cars were 400hp, 432ft lbs, supercharged were 510hp and 490? i think torque. The tune was off on the S/C cars until later years so alot of motors blew.....also later on he started using forged internals not the lightening shortblock. He did have a company in Texas assemble the engines and then shipped them to Calif. Also he put in a 3550 Tremec then in 1997 switched to a 6sp. Sure he could have got more power BUT he had to warranty the cars also.
MM&FF took a 1996 N/A car and got it in the 12's with slicks and got it up to 165mph. They also got a supercharged car with a slipping clutch to run 11.3's in the 1/4mi. The S/C cars trapped around 122mph in the 1/4mi. I have also heard that the 0-60 times of the N/A vs S/C were very close......traction is a problem
Back in 1997 or 1998 Road and track tested a S/C car and said it walked away from a Viper. Vipers were rated at 450hp at the time, they had 17" wheels while the Saleens had 18". S351's were the S**T and I drooled everytime I read about one.....but I was broke and NEVER thought I'd ever own one!
On Thursday when I go to my buddy's shop I will ask what the guy who did a 351 swap on his 94 did.
I saw one on Ebay for around $100.
... and finally sided with a 1:1 ratio being the norm of 90% of cars I see.. 
flame suit on: .. A street H/C/I 351W will put out roughly 350rwhp vs a 302 H/C/I 302rwhp vs a blown stock 302 @ roughly 302rwhp $ for $. Now if you go more radical H/C/I 302, you can build it to the NA power of your mild street 351 but it still wont have the low end. If you put a blower on a H/C/I 302 then its no comparison to a mild 351 build..but then we are apples and oranges.
