I have asked this question before, but I am seriously looking into a rear end pumpkin swap. I have a 5AT (5.3 gears) and am installing the Vortech SC. I have a friend who has a 6MT (5.5 gears) who has the HKS SC. He is wanting to install the 5.3 gears in his 6MT to be able to better utilize his power. I have been wanting to move up to the 5.5 gears. So my question is this, with my having the 5AT (5.3) gears, would it HELP or HURT me to do a complete rear pumpkin swap with him. The obvious good thing about this is that it will only cost us both the labor to do the swap. I know many have said you dont want to do this with FI, but I dont readily remember about swapping the AT gears for the MT gears.

TIA
Zach

 

i think if you plan to go up to 400whp a 3.5 will help

above 400whp and the 3.3 is probably even or better

 

I was originally shooting for about 380 and after seeing several 5AT Zs puting down over 400, thats what I am now shooting for. I would like to see around 410-425 or so.

 

Any other comments guys?

 

I would be more likely to leave it

or at least leave it and after you get to 415whp decide if you want each gear to have more power

I'm going to be putting a 3.3 in my car when I reach 410-440whp. I figure it'll be more fun not spinning out tires in every gear

 

Shorter gears means harder acceleration and more tendency to break loose under full power. Several of the boosted 6mt guys have swapped in the 5at rear end so they get a higher mph in the quarter...you don't have to shift at the end of the quarter like with the 6mt gears. For your car I guess it depends if you are street driving or 1/4 mile drag racing.

 

I will drive the car on the street as well as at the drag strip. I dont care about top end. I just want to get to whatever it is quicker.

 

The 6MT is quicker if you can keep your tires on the ground.

 

But would I benefit from this mod. I wouldnt want to install this if its not going to help me. If the general concensus is that I should keep the 3.3 gears, then thats what I am going to do.

 

shorter gears= less traction but faster acceleration if you can get traction.

 

5.3s damn you got tractor gears

With an SC and 5AT the 3.5s are a good swap as long as you getta good LSD (at least the OEM VLSD) , No open diff

For TTs , the 3.3s and a good LSD work best.

Note that if you swap from the factory your Cruise control will not work properly. As far as I know ,no one can correct thios yet.

 

I've thought about the same thing but wasn't sure, I have a 6mt now and thinking of going with the 3.3 final drive, anyone willing to swap in the atlanta area?

 

tonio,

i am in southeast tn. i'll swap with you. pm me.