transmission swap

[rfmaster]

Stoke

ECM (1227747) controls 700R4 lock-up via three wire interface (white four pin connector), but you'll also need to wire brake pedal switch for TCC release function. It is a very simple two wire circuit.
After market harnesses are nice - wires are higher quality and connectors are not broken. Otherwise you'll need to exercise care when removing harness from '88 donor. BTW if IIRC I used 2-1/8 52mm GreenLee tools hole punch for the firewall though hole (just because I had it around). Worked like a charm.

//RF

[shrtbx]

another thing people overlook ( I myself have done the same), is the rear end gearing. 3:08s and 2:73s are no good for the 700 r4. The Overdrive gear wont function right. This is the second swap i have done as far as engines and im finding out you really have to pay attention to the small things. You might want to get a new gear selector too for the dash, not a big deal but they are different.

[Pyrotechnic]

As I guideline, I say that 28" and under tires are good with at least 3.42 or higher, and larger than 28" tires need 3.73's or 4.11 depending on how tall your tires are. Although thats just a guideline. The big thing is that you aren't lugging the motor in overdrive or having it downshift to 3rd often.

[MylilBowTie]

Originally Posted by shrtbx

You might want to get a new gear selector too for the dash, not a big deal but they are different.

The steering column for the three speed th350 is different than the one for a 700r4.

[CavScoutsC10]

that's what i have on my chassis now. a 350 lt1 with a 700r4. i didnt have to make any changes thus far. i do know that i have to use a different driveshaft.

[rfmaster]

Cav

Are you going to run mechanical spedo???? You may need to invest into external VSS and old style driven gear case from older 700R4.

How big are those fuel lines feeding your injection system (supply/return)???

//RF

[CavScoutsC10]

i haven't gotten to that part of the build yet. but, i've been looking at getting the manual speedometer so i can keep the original instrument panel and keep VSS.

the other option is to keep it electronic and get a digital panel. but that panel is about 550. that's a little steep.

the fuel lines are for a 94-97 camaro. so it should be enough.

[rfmaster]

Cav

If you are going to get external VSS to work with conventional mechanical speedometer make sure that you know how many pulses your ECM or PCM is expecting. Older C3 ECM which were used with TBI expect VSS to produce 2000 square pulses per mile. You probably know this but later PCM expects VSS signal input to function properly. According to JTR a 40 pulse per driveshaft revolution speed sensor was used on 1993 and newer trucks with automatic transmission, 1994 and newer rear drive cars with the automatic transmission. An external VSS is a lot cheaper than new digital dash.

That should be a sweet running truck when it is all done.

//RF