Ok guys, the inside of the hood reads that Ive got a spicer 70 and it says 3.5 i guess thats with the gears r something. My question is, what are you able to do as far a top speed with this rearend. Its a 4-wheel drive and I havent messed with the fuel screw yet. Thanks, Will

 

Hope thats enough information to tell.

 

It should run 85 or so flatfooted with the 386 spring

 

mine with the 5speed and 3:54's will run above 85 with the 366 the blue truck tops at 80 without the 366 gov spring.

 

Thanks for the answers guys, ive got the 366 spring on the way, and a piston lift, and goin to put the denny t pin in tomorrow. If im by myself can I turn up the fuel screw and get to the turbo fast enough to block it off if it starts to runaway?

 

when turning up the fuel screw take off the intercooler tube from driverside of intercooler to top of engine then have a block of wood with ya.. as you turn up fuel screw if truck starts to run away put block of wood over intake pipe on top of engine and it will kill all the air to engine and it will choke it self off.

DO NOT put block on wood or anything else on turbo side. cause you could have serious issue if something gets sucked into the turbo.

 

Thanks, prolly saved some of my fingers bruiser.

 

I've had mine up to about 90 mph on a quick burst of highway driving and there was still room left to go faster. After a governor spring the power unleashed is scary the way the engine used to perform, but it still sure is fun.