ta3ff

Here's my quick question, is there any difference between an auto and 5spd 305 730 ECM? I have a 1990 730 ecm which was from an auto car. I know the auto's have a TCC terminal and a few other things for auto's.

Any advise will help. Also, I tried the seach but no luck. If theres a thread on this please let me know.

Thanks.

fisherbody86

No. The only difference will be in the PROM. The ECM will have the programming and circutry to run either an auto or a manual. The MXO cars will have a different harness and PROM than the MM5 cars, but the same ECM. I swapped my 700R4 out for a T5 more than 2 years ago, and am still running around with with the auto PROM and the transmission connectors hanging under the car without any problems. Not even a SES light or trouble code!

ta3ff

Thanks a lot fisherbody86, since I've read a ton on auto to 5spd swap nobody mentions ecm or prom promblems. I just wanted to make sure. Thanks again.

ta3ff

fisherbody86, I forgot to ask, what rear end ratios are you running? I'll be swaping in a 3.23 posi. Is that pretty good for a 5spd? Thanks.

xandersdad

That's what my 86 with a factory T-5 has is 323 gears but not posi.

fisherbody86

Well, at first I had the stock 2.73's in there from the automatic. Without a torque converter, the new 5 speed was a dog off the line. Then I put in some 3.73's. Oh yeah! Those were some good gears, except the car would top out (speed limiter coupled with inaccurate speedo) at 98 MPH. That was simply unacceptable. But the pull was strong, even for a modtly stock 305. It would kill the tires in 1st and 2nd. Super sweet. Then I grenaded that gearset, and now I have a set of 3.27's in there. Kind of poochy off the line, but all around good cruising gears with highway power and grunt in the lower RPM range.

PS. If you're converting from auto to stick, I recommend some kind of firewall reinforcement around the clutch master cylinder. Otherwise you can run into the problem I had. I cracked the firewall around the clutch master, and it was EXTREMELY time consuming to fix it (car was down for 8 weeks!).

ta3ff

I only asked my original question because mine is the ol' boring tbi. It's currently an auto, but and here's a big BUT, I have the chance of getting basically the same car as mine but 5spd.

I will be switching over to TPI, the TPI's trans shifted really nice unlike my beat up TBI tranny. Is a 5spd better than an auto? After the conversion over to TPI I'll be doing what most guys do, SMASHING it.

I just want a fun ride, so auto or 5spd. If I get the 5spd, I'll have to deal with haggling for a good price and not to mention the registration fees.