Question on Gearvendors overdrive . Is it a basic bolt in operation for a

I bought a used one for a ford transmission. traded in the ford adapter + $750 if I remember right for a 904 adapter at gear vendor. My thoughts on used if you can pick them up for under a thousand dollars you are probably fine. Gear Vendor will rebuild them or exchange the unit if it doesn't work for somewhere in the neighborhood of $1,000. I think a new unit is about $3,000

It don't think it will lower your cruise by 1200 rpm. My car has 4:10 gear 28" tall tires and I run about 70 to 75 on the fwy, the rpms are about 2800.

Gear Vendor says no tunnel work required. Most people that install say they had to hammer the tunnel on the A body cars. I chose to just lower the transmission about a 1/2" on my install. Someday I might hammer the tunnel to get the trans back in the factory position.

Overall I'm really happy with my gear vendor and yes I would chose one again. It's a great item for a true street strip car. Although I didn't see any benefit in mph or ET when split shifting during drag racing. The gear vendor makes freeway driving so much nicer.