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What should i do next?

633 Views 4 Replies 4 Participants Last post by  Cruzer
I have a 68 coupe with a 289 with the following modifications. holley 600 cfm carb, holley street dominator intake, petronix ignition, accel super stock coil, Tro-y Headers, 2 1/4" flowmasters and dual exhaust. and i have a rebuilt (stock) C4 and 2.79 gears. I want to know what will make the biggest improvement in the quarter mile without killing the drivability (daily driver). torque converter? Rear end swap? Cam and Lifters? Roller Rockers? i do plan on running nirous but i was going to save that for the last mod. Any ideas? TIA

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
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I have a 68' pretty close to yours with the exception of a Comp Cam that operates @ 2200rpm. What I did this winter was change the 2:79's to 3:25's. I wanted better low end and I think this will help, I'm a little afraid of the gas mileage when spring finally gets here in the north east and we can get back on the road.

68' LIme Gold Coupe
Rear gears, biggest bang for the buck! 3.25 or 3.55


1966 Mustang Coupe, 302 custom roller cam, holley 650dp,
I agree, get the gears changed.

Can you smellllllllalalalala........?
66 coupe 289 2v C4 needs restore
70 coupe 351W 2v c4 almost done (?)
We have basically the same engine but I have a hi-performance cam. I added 3.25 gears this past summer. Go with a hotter cam & add the 3.25's. You'll love the power. As for the NOS, be careful. Depending on the horsepower shot you want 50, 100, 200 hp is a lot! Your engine better be in good condition in the lower end. Or you'll have pistons going places they weren't suppose to go. Put a 50hp NOS on my son's Honda. It was like adding another passing gear. Nice power increase.

66 Coupe, 302, Auto, 3.25 gears. [color:red]Candyapple Red</font color=red> with White Pearl Stripes. Cragars.
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