402 Big Block

[ferg2571]

Just bought my 2nd k5 84' Jimmy and ready to start its transformation . My question is what would be the best tranny and diff set up would be . Startin with a 402 bb . truck has a 700r4 not sure of the transfer. any suggestions or info would be great .

 

[kevin400ex]

700 wont last long behind a bigblock. if you want auto t400 is the way to go. 14bolt in the rear for sure.

 

[Hogback Fabrication]

What do you want to do with the truck? The trans/diff setups will vary greatly based on that.

 

[ferg2571]

Nice rig man! Kind of want the best of both worlds with this rig . want to be able to do some light to intermediate wheeling ,but be able to take a hard core challenge every now and then . Also want to be able to drive it where i want trips to Moab , Ouray . Basicly be highway ,interstate able also.

 

[trevmountain]

My set up is a built 454. Makes an estimated 450-475 hp. T-400 tranny built. Dana 60 up front Gm 14 bolt in the rear, gearing is 3:73's. The motor makes a ton of power so the gearing can be a little high. It will cruise down the highway at 80 no prob but will to good a low speed as well due to the power of the motor. The Turbo 400 tranny is 3 speed bullet proof tranny and will do fine with high horsepower motors. If you want a more capable trail rig, crawler I would gear it down to 4:11's or 4:56's but I wouldn't expect to go much over 60 miles per hour.

 

[brooks294x4]

60 front 14 bolt rear nv4500 or T400 depending if you like stick or auto 205 case all solid parts that can handle anyhting that you mentioned. 4.10 gears should be fine as long as your not goin with huge tires

 

[496truck]

700R4's can be built to take the abuse. If you are going to be traveling the highway with any sort of frequency this will be your best bet. Be sure to use a decent trans cooler, heat kills auto transmissions. Talk to your local trans shop or look for a recommended builder in your area. Tell them what you are building and what you are going to use it for and they should know how to build the trans for you.

T-case will vary depending on your intended off road use.