Vintage Mustang Forums banner

1 - 5 of 5 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I have a 68 mustang with a 289, c4, street dominator intake, holley carb, tri-y headers flowmasters, petronix and an accel coil, with 2.79 gears. I want more performance. BUT it is my daily driver so i dont want to give up TOO much on the mileage side. I plan to make the switch to a T-5 to help with the mileage and when i do i will probably swap the rear end gears. But i was think a bout a plate style Nitous setup to give me the power i want without losing the mileage. Whats involved in this do i need to change pistons? what other parts will need changing? i plan to run a 100-125 horsepower shot.

1968 Mustang Coupe - Daily driver
289, holley 600 carb, holley street dominator intake, petronix ignition, Accel Super Stock Coil, Tri-Y Headers, 2 1/4" 2 chamber Flowmasters, C4 and 2.79 rearend
 

·
Registered
Joined
·
10,587 Posts
Matt,
Keep the C4...put a shift kit and 11" converter in it..
Put 3.25's in the rear with a T-loc
Use a 100hp nitrous setup....no problem with your engine...run an electric fuel pump to ensure adequate fuel flow

Total cost....around 1.3K.....you do the work...
Performance....mid hi 13's with some tuning...corked up on street tires...

Nice sleeper...*G*

BTW...going to 3.25's won't hurt your mileage much....I got 15-17 on the freeway with my street racer '67 and 3.50's and a C4....car ran mid-low 14's with that gear naturally aspirated...

Pat
http://albums.photopoint.com/j/View?u=1570936&a=11937754&p=42910787.jpg
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
Hey pat what kind of cam were you running in that engine?

1968 Mustang Coupe - Daily driver
289, holley 600 carb, holley street dominator intake, petronix ignition, Accel Super Stock Coil, Tri-Y Headers, 2 1/4" 2 chamber Flowmasters, C4 and 2.79 rearend
 

·
Registered
Joined
·
1,667 Posts
I think the concern there is whether the T5 will take the power or not. The T5 was designed for 4 and 6 cylinder cars. It has had some stuff done to try and make it strong enough for the stock 5.0's but its still not the greatest. Some of the T5's are rated at only 265 foot pounds. Your nitrous shot will make more than that. Most of the 5.0/T5 racers I talk to say Its not whether one will break but when.

There were some things done in 85 to help the T5 so the 85 and afters are supposedly stronger. There are some pricey T5 units that hold up pretty well and are rated up over 300 ft pounds of torque. These are called the X, Y and Z T5's. You most likely won't find any of those at a salvage yard.

For NOS I would run forged pistons and a separte fuel line including a fuel pump just for the NOS.





You can see my 65 fastback at: http://hottarod.stangnet.com/
http://members.aol.com/macstang/Gifs/macstang3.jpg
 

·
Registered
Joined
·
10,587 Posts
That car and combo are long gone...sold it back in '84 to buy my first house...

IIRC the cam was an Isky solid lifter with specs a lot like the SVO A311...mild piece similar to the HP 289 factory cam...
Had flat-tops, mildly ported heads, an Offy Dual Port manifold and an old Holley 650 spread bore carb (like a quadrajet)...
I think the small primaries on the carb and the dual port manifold helped with the economy but likely hurt performance a bit...car should've been in the high 13's (ran 14.00/100mph with 4.62's)...

Any other questions?

Pat
http://albums.photopoint.com/j/View?u=1570936&a=11937754&p=42910787.jpg
 
1 - 5 of 5 Posts
Top