ok i have a 2004 carlo.

current specs:
3100 v6 (swap from 3400)
4T65E tranny and my gears are shifting slow.

this local guy has a carlo 2006 3900 engine and trans that i want to swap.

1. is it possible to swap these two?
2. and is it possible to swap just the trans? (Im not sure if the 06 is a 4t65e)

thank you.

 

why did you drop in a 3100 in the first place

 

because i had the 3100 before i bought the 3400 and after using it for a hefty time i hit 300k and put in the 3100 which is now at 164k the 3900 has 73k

 

the 3.4 is the stock engine after 99 the 3400 replaced the 3100 its a 20 hp diffence and the same block 3900 engines are hardish to find its basically a 3800 bored alittle your car could fit it but as far as stock goes that year had the 3400 3800 and 3800supercharged
you can do the swap its the same fram you do need the computer from an 2006 for the engine tho most likely or the engine information put into the computer you have now

 

well the guy is selling me the 06 carlo not just the engine and trans. its just wrecked in the front but for 800 i will strip this thing for all she's worth.

thanks but my last question is would i be able to just swap the tranny? or would i need the engine to go with the 3900 tranny.

 

The 3900 isn't at all related to the 3800. It's its own animal, but it takes it's roots from the 3100/3400/3500's (it's a 60* v6, whereas the 3800 is a 90*). The problem is that it's a new generation pushrod v6 with VVT. It's not really a direct swap because you will need all of the wiring, PCM, etc. If I were you, I would look into a 3500. It's a bit more performance and can be swapped a bit easier (but you will still have to modify that to work too).

 

I second this motion. From what little I've seen of the 3.9, it does not look related to the 3800 at all, appears it's a 60 degree v6.

If you are doing this to have a reliable engine, don't make it harder then it needs to be. Get another 3400 and pop it in. If you are doing this to increase performance and want to do it on a budget, you might want to look into a L67 swap (has been done many times, lots of information on it and it's an engine that was offered in this generation Monte).

If you can afford the down time with the car and it's a project car, then sky's the limit. Find the road you want to take and have fun with it.

 

From what I have learned from Will at Overkill, you can swap the 3900 transmission, but the gearing is different and you will need your PCM tuned to handle it.

 

OK. As for right now i just need a trans that will fit the 3100 i have now and later if i upgrade to a 3400 also. What other cars would have a compatible trans?

Im having a hard time finding this trans and if i do its at a shop for $800+ thats too much considering this guy is pitching me his 06 carlo for less than that. If i can't find a cheaper route i will eventually go with the 3900

btw im in charlotte, nc
please help!!thanks

 

Here is the email I got from Will at Overkill when I was looking to swap my transmission in my 3400 Monte. It might help you out...

What I would suggest is finding a young transmission from a 2005+ Buick LaCrosse 3.8 or 2006-2008 Grand Prix 3.8 non-supercharged, something along those lines. If you get the transmission from a 2006+ Impala with a 3.5 engine, it will have the same gear ratio as yours (2.86) and should swap right in. If you get a GP/Buick transmission as mentioned, it has a 3.05 ratio and I can reprogram for it. If you want even more performance, you can get an Impala 3.9 transmission which will have 3.29 gears. Keep in mind as the ratio increases, performance will improve but cruising rpm will go up and fuel mileage will go down.

Just about everything 03+ is interchangeable in terms of capatibility. Go for something low mileage and well priced.