4.30 gear swap complete

[Grn92LX]

First off I gotta thank my buddy Sam (Ninjacoupe/Pony772 on the boards) He helped me out BIG time!

The install went fairly smooth except for a few snags along the way, but we all know it NEVER goes 100% right. We built the rear outside the car and then put it back in. I went with the 03 cobra 31 spline differential, FRPP 4.30 gears, moser 31 spline axles and all new bearings, races, shims and seals with Amsoil synthetic gear oil. I got it up and running on Thursday and all was well except for a slight hum on decel. We tightened up the pinion nut and that cured that problem.

As for the overall feel and streetablity, driving around town normally isn't much different than the 3.73. It definatly rev's much quicker when you get on it I took it on the highway last night and it was fine, didn't rev too much higher than my 3.73.

The gears should give me another 3-5mph and let me use that last 1000 rpm's of powerband the 3.73's weren't letting me use.

 

[5spd GT]

What rpm were you cruising at 60 or 70mph?

Good that you got it going...the gears and you learning to drive that combo better should get you 2-3mph more...let us know your track results when you go...

 

[Grn92LX]

The highway rpm's were between about 2300 and 2700. Its rare that I go much more than 75mph. 65-70 mph is normal for me so figure that. The speed limit is 55 here so I dont wanna get bagged by a NYS trooper.

Next up is installing my 3" X pipe and setting the pinion angle. I would like to hit the track before it starts getting too hot. I also need a better tire. Thinking about having my rear wheels widened 1" so I can fit a MT 255/50/16" drag radial. tire My goal is 120 mph trap.

Forgot to mention I also went with an LPW girdle and bearing cap studs. It looks good painted gloss black with the aluminum girdle

 

[Hissing Cobra]

Awesome! You'll like that combination. Both my brother and I have those gears and run low to mid 12's with our 306's. Your new engine, combined with the gears, should get you where you want to be. Have fun!

 

[5spd GT]

Does your speedo not work?

 

[89white50]

what speed was with 2300 rpms???? with my 327's, at 75 im at almost 2500, minus a couple cuz if ****ty stock tach and im at about 2400 at 75. I drive a LOT of highway, and i dont know if i could stand spinning it any higher. 2700 rpms?? jez man, thats a whole lot of wear...are ya thinking about a 6-speed swap?

 

[5spd GT]

I'm at 2,400rpm with 373's...70mph (interstate speed)

I'm sure with the 4:30's, he is around 2750rpm...

My friends with 4:10's are at 2,600 or just a tick above that...so the 4:30's will be higher...I'm with you 89White50...but Mike's car isnt' a daily driver so it is perfectly liveable for a street/strip car.

 

[Grn92LX]

what speed was with 2300 rpms???? with my 327's, at 75 im at almost 2500, minus a couple cuz if ****ty stock tach and im at about 2400 at 75. I drive a LOT of highway, and i dont know if i could stand spinning it any higher. 2700 rpms?? jez man, thats a whole lot of wear...are ya thinking about a 6-speed swap?

6 spd swap? Hell no! I would love a built AOD with a manual VB and a killer stall

How can you say its a whole lot of wear (which it isn't) when you said you cruise @ 2500? How is 200 rpm's a "whole lot more wear"? A few extra rpm's don't bother me. I geared the car for the powerband. No sense half assing a combo, the 3.73's were a big bottleneck so they had to go.

My PMS screen shows the exact engine rpm. Next time I go out i'll try and report an exact rpm for you.

5spd, the speedo works but there isn't a speedo gear for 4.30's so it reads higher.

 

[Hissing Cobra]

I cruise to Connecticut at least twice a year and New Hampshire two or three times per year, plus attend a car show that's 45 minutes away just about every Sunday and mine is at 3,000 rpms @ 80 mph. That 3K doesn't bother me at all. I make power on the dyno all the way up to 6,400 rpms, so 3K is only in the middle of the powerband for me. I wouldn't change a thing.

 

[Nick302]

You have a very unstreetable street car, you should join a club.

 

[Grn92LX]

You have a very unstreetable street car

Is that why you stood me up friday night homo?

 

[89white50]

i wasnt trying to be a dick, But since my motors mostly stock it bothers me more. hahah ill have that new feeling like you guys within the next year. i had no idea you had an AOD. i alway thought you had a 5 speed. interesting, that completey changes my thoughts on the 430 choice...

 

[Grn92LX]

i wasnt trying to be a dick, But since my motors mostly stock it bothers me more. hahah ill have that new feeling like you guys within the next year. i had no idea you had an AOD. i alway thought you had a 5 speed. interesting, that completey changes my thoughts on the 430 choice...

I have a tremec TKO. I said I wouldn't mind a built AOD.

 

[6SpeedLX]

ive just been too lazy to put my 4.30's and 31 spline conversion in...i think ill get that done asap now....