4th Gear Poster
Join Date: Dec 2011
Location: Kingston, Ontario
Mark VIII 3.73 Swap
I'm back to daily driving my Mark VIII now and the stock 3.08 (3.07's?) gears are getting real old. Sure the gas mileage is great on the highway, but the gearing is all wrong for a high revving DOHC engine with crappy low end torque and no VVT.
I've found a used trak-loc for a great price and will probably get some FRPP 3.73's to go along with it.
Now, I'm finding wildly varying opinions about what's needed to support this swap.
First, I know I'll need a purple speedo gear, but that's easy.
Secondly, I've got a 93 Mark, with the aluminum ds, and zero vibration at highway speeds.
What I'm really concerned about is whether the tranny's tailshaft will be starved or underlubed (I do about 80-90% highway driving, but mostly around 70mph or so) and whether I'll bang into the rev limiter on WOT shifts. I don't track the car FYI and it's just a daily driver with the occasional WOT run.
Some say yes, others say no.
I probably will j-mod the tranny at some point or at least change some springs, but for now it shifts decently and I don't feel like tearing into the tranny.
If going to 3.73's will create a ton of new problems, I'll just live with it, but it'd be nice to hear from others with experience.