I am going to be putting in the TH400 in a couple of weeks...my 6-speed Idles around 800-900 right now...will it change when I do the swap??

The cam specs are in the sig.. <img src="gr_stretch.gif" border="0">

Thanks... <img src="gr_stretch.gif" border="0">

 

Brian, how much power are you really planning on? A TH400 with that 4500 stall you mentioned is honestly going to make your car a lot less fun to drive on the street than a less hard core setup might. I don’t know what your plans are, but unless you’re going to go “track only”, I’d really consider a well build 4L60E for a mostly street NA build up. I know you were interested in an ATI in the past, and if that’s still in the plans then maybe a turbo 400 is right for you, but IMHO you should really think over your goals before going TH400.

Just to give you a couple of examples, I used to have a ’71 Cutlass with a turbo 400 and a SBC motor. It had a very low stall ‘verter (like 2 grand type of low) and obviously no lock up. It was really not that bad with the granny 2.XX gears that were in the car, but even still the revs were pretty high on the expressway, and gas mileage sucked. My friend Mark had a ’83 Grand Prix with a BBC motor and a 4.11 rear with a TH400 (I don’t know what stall he had though) with also no lock-up. That car turned 4000rpm at like 70mph. Even on the street it sucked big time for both gas use and motor/exhaust noise. All those excessive rpms just to cruise at normal speeds really took it’s toll on that motor over time. That motor didn’t last long setup like that on the street. With basically no track time at all that motor was knocking with just street miles pretty quick. If you keep your 4.10s it’s really going to be bad on the street. I really don’t think you’re going to have a lot of fun with it like that.

Obviously it’s your car and your choice, but I’d just hate to see you regret such a big decision later on down the line. Your car is cool as an M6, but if you really want to go auto, give overdrive a second thought. Talk to Izzo about the new 4L60E that he’s offering from Louisville. That’s the one I’m going with. It’s built with a pretty impressive list of parts, and I’ll bet it’s gonna hold up pretty well. An FLP Level IV would also be a great choice.

BTW, I don’t think you ever told me why you want to ditch your M6? Did you just get sick of shifting gears? M6s are really cool on the expressway. They’ll mess up autos at similar power levels.

Whatever you decide, good luck man <img src="gr_stretch.gif" border="0">

 

He bent the 3-4 shifter fork.
Normally there's a TSB out for it which would be repaired free of charge.
However, I can't see any dealership around here even THINKING about warranteing his car.
In the end, Brian figured it would be cheaper to swap to A3 instead of having the T56 rebuilt.

 

[quote]Originally posted by BlackWS6:
<strong>He bent the 3-4 shifter fork.
Normally there's a TSB out for it which would be repaired free of charge.
However, I can't see any dealership around here even THINKING about warranteing his car.
In the end, Brian figured it would be cheaper to swap to A3 instead of having the T56 rebuilt.</strong><hr></blockquote>

How much does a T56 rebuild cost?

 

I must say i do agree with RPM WS6, a friend of mine has a 86 grand prix with a 305, mod'd, backed with the 400 and 3.42's, Within one evening of cruising around we had to fill the gas tank up twice, but that was in town, so i figured highway has to be better, we'll cruise the highways, it wasn't much better.... Definitly a once in a while, only at the strip/car show type setup. But then again, some people are more tolerant of that stuff than i am. Myself i am a very picky person, if it doesn't go the way i want and feel comfortable with, it'll just have to be changed, but that's me. Have a good one.
<img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
Brandon

 

[quote]Originally posted by RPM WS6:
<strong>
My friend Mark had a ’83 Grand Prix with a BBC motor and a 4.11 rear with a TH400 (I don’t know what stall he had though) with also no lock-up. That car turned 4000rpm at like 70mph. Even on the street it sucked big time for both gas use and motor/exhaust noise. All those excessive rpms just to cruise at normal speeds really took it’s toll on that motor over time. That motor didn’t last long setup like that on the street. With basically no track time at all that motor was knocking with just street miles pretty quick.

</strong><hr></blockquote>

no offense her man, but if you have a nice new built motor and turn 4000rpm @ 70 on probably now more than 2500rpm? on that street and your motor starts KNOCKING.....the trans wasn't the problem. Something in the motor was, i mean come on think about it.

i have a crappy 4 banger with no o/d and turn 4000rpm @ 75 on a regular basis driving 25miles to my job everyday on the highway and the motor hasl ike 70k miles on it and it isn't knocking.

Something was wrong with that guy's motor

 

Ryan I do plan on going with an ATI down the road or as soon as I get the cash...I want to put stage 2 heads on the car also....an ATI on top of that running 5psi would make some nice power...I will also be upgrading to a 9" rearend, and will most likely swap a 3.73 gear in it for a while...that would make me around 3400 rpms at 75 on the highway...Macgyver turns 3900 at 75 with 4.11's...

<img src="gr_stretch.gif" border="0">

 

[quote]How much does a T56 rebuild cost?<hr></blockquote>

I've done some checking since I'm going to need to put new synchros in mine sooner or later ... ballpark cost is $1000 to $1500 depending on what needs to be replaced ... I wouldn't expect to spend over $1500 on a rebuild. Brand new T56 replacement will run around $2900.

 

[quote]Originally posted by JimmyKash:
<strong>

no offense her man, but if you have a nice new built motor and turn 4000rpm @ 70 on probably now more than 2500rpm? on that street and your motor starts KNOCKING.....the trans wasn't the problem. Something in the motor was, i mean come on think about it.

i have a crappy 4 banger with no o/d and turn 4000rpm @ 75 on a regular basis driving 25miles to my job everyday on the highway and the motor hasl ike 70k miles on it and it isn't knocking.

Something was wrong with that guy's motor</strong><hr></blockquote>

Actually, it wasn’t a new motor. It had lived in another car that had a built 700R4 with OD and lock-up. It ran fine in that car, and it seemed to go shortly after he was using it on the expressway regularly. You’re right though, their could have been other issues...

Brian, if you are planing that much power than maybe a TH400 is for you. I just hope you don’t miss shifting gears <img src="gr_stretch.gif" border="0">