If the gear ratios are different can I have mine changed to suit the cutlass tranny. Or should I just ingnore the high revs as just the way the tranny will work in my bonne. :? :?

yes

http://60degreev6.com/showthread.php?t=25032

Ok, so taking the info from JR3800 that my 88 sse has a 2.97 ratio and the cutlass' tranny was set to run 3.33. That means that my engine has less teeth on its side of the chain than the tranny. So it is going to have to run with more revolutions(work harder) to acheive the same shift pts than when the tranny was in the cutlass. This is like when you go to a lower gear on a 10 speed bike to get more of a workout without making the bike go faster, right? Now, my next question is, will this bring my engine to a quicker demise, or can I take any computer parts or my whole ecu from my cutlass and drop it into my bonne and have things change for the better or not? Or do I just take care of it until I can afford to have my original Hydromatic rebuilt? :P

Werd. GX3 tends to keep the car in the higher revs, out of the powerband.

I love it when I am enlightened! Makes me feel like I'm in high school taking my car apart and putting it back together again, only w/o the tools and the mess! Now, do I worry about any damage to my engine from working harder than usual to get the shifts? If so, do I try any of the computer stuff frm my cutlass on the bonne, or is this going to be a custom job? I plan to either get the old hydromatic rebuilt by AAMCO in the next year.

Hmm, "working harder" is not really the right way of looking at this. In fact, the engine is working easier with the higher gear ratio. The transmission is providing more mechanical advantage to accelerate the car, so the engine doesn't have to work as hard at moving the car.

Make sense? The higher gear ratio came out of cars with an engine that had a higher rev limit and produced less power across the board (the 2.5L 4cyl, 2.8L V6, and 3.1L V6.) Kinda like my '87 2.8L V6 Camaro that came from the factory with 3.23 gears as opposed to the 2.xx gears that were stock in the V8 cars. The numericlly higher final gear ratio tried to make up for the dismal power output. If I remember correctly, the 2.8L V6 capped out at 6,000rpm redline (6,500rpm cutoff) vs the 5,500 rpm limit on the SBC V8.

Now, the $1,000,000 question: What is the practical RPM limit on the 3800 (LN3 style) ?

If things work the way I'm used to seeing it happen, valve springs are normally the first limit to the engines RPM limit. The stock springs can't close the valves fast enough and they end up floating. (Not normally hazzardous to the motor, unless you have piston crowns that intrude into the chamber...the motor just falls flat on it'* face and doesn't want to accelerate any higher.) The correction is to use stiffer springs in the valve train.

Next limit is usally airflow on the intake side..the heads just can't flow enough air to keep up with the motor'* displacement at that rpm. Solution is typically better cylinder heads or porting of the stock heads. Following this is: Airflow on the exhaust side, piston speed, wrist pins, connecting rods, crank, and bearing failures. (the last being in the rediculous rpm range.)

So, from a practical standpoint, a higher gear ratio is usually a good thing if you like to go quick. Unfortunately, I don't have the experience with the 3800 to know when these limits normally get hit. But I'd wager a guess there'* a few around here that do

Ok, so I read that backwards and my car having a lower fdr is better for my engine, right? :?

dont think if it in terms of better or worse....the lower FDR will give you better gasmilage, but slower acceleration....the higher FDR will give you worse gasmilage but faster accelleration

So this is not hurting anything for it to have the high revs until I rebuild the OEM tranny?