I have a 1978 GMC half ton pickup with full-time 4WD and either a 454 or 400 C.I. engine(can't find any numbers on the block and it's not the stock motor, seller couldn't give me any help on it). It has a 3-speed auto tranny, but as you may well predict.. a 3-speed with a 400+ c.i. motor isn't exactly an economy mobile. At the junkyard the other day I saw a mid-80's Chevy, and since I was looking for a couple window cranks I jumped in, and to my surprise saw OverDrive on the shift column. Is it possible to swap a 4-speed OD into my truck without much problem? I wasn't sure if there was any big electronic issues with doing it. If so, what's the transmission code that would work in it? Thanks SO much in advance. My 7 miles per gallon thank you and are looking for friends.
2006-11-16 16:51:36 · 4 answers · asked by Ryan M 1 in Cars & Transportation ➔ Maintenance & Repairs
I'd actually like to put a smaller motor in the truck, I'm looking for a way to get rid of the motor in lieu of a 350, then mating that up with the 700r4. For the 4L60 or 80, how much of a pain in the tail is it to hook it up with the stand alone ECM?
2006-11-17 03:54:22 · update #1
doesnt matter what motor u have big block or small block. here is what u do seeing how u have a truck and to build a 700R4 to take the torque of either motor is pointless. go buy a 4L80E or a 4L60E either will work there are companies on the market that make stand alone ecm's for these transmissions. bolt it up hook up the ecm and go. it will work trust me i have an 80 olds cutlass supreme with a 350 sbc and a 4L60E out of a 98 chevy truck and a stand alone ecm from B & M and it gets great gas mileage
2006-11-16 19:18:03 · answer #1 · answered by marc s 3 · 0⤊ 0⤋
A 454 is a big block and a 400 is a small block. The 400 would only have 4 bolts on each valve cover.
The bolt pattern should line up. Go for an early 80's 700 R4 with little electronics.
2006-11-16 17:05:54 · answer #2 · answered by Anonymous · 0⤊ 1⤋
its called 4 speed + overdrive basically because its an Auto, if it was a stick shift then ya it would be called a 5 speed, because in a manual transmission in a 5 speed the 5th gear is overdrive gear and in a 6 speed the 6th gear is overdrive, also in an auto transmission it doesn't need the Overdrive to function properly so it doesn't need it, overdrive is just for highway and interstate driving so don't have it in Overdrive for normal everyday driving unless you go on the highway or interstate an Auto isn't going to have an Overdrive gear unless it says its Overdrive with the O with the D in it, if a 5 speed Automatic doesn't have the O with the D inside it then its just a 5 speed with no Overdrive, the gear ratios of the 5 speed with no Overdrive would be closer to each other
2016-05-21 22:04:34 · answer #3 · answered by Anonymous · 0⤊ 0⤋
It would depend on the donor transmission year. Some of the late model are computer controled. Most likely you are talking about a 700r4 trans. They are super as long as you get them set up right at wide open throttle. You can buy an inexpensive aftermarket lockup kit to lock up the converter. You can not drive in lock up if you are pulling hills or have a trailer on.(weight) These trans drasticly reduce engine rpm Hope it is an early model trans. Good luck.
2006-11-16 17:08:30 · answer #4 · answered by ? 4 · 0⤊ 1⤋