BBB 455 and TH350

[Slowpoke]

No neutral drops and you'll be fine
Get on that Th200r4 soon, you never know. Also consider your highway RPM as well. With 2.41s and half bald 195s and a th350 I'm at 2500 at 75mph. With aTh2004r and no other changes, it'd drop down to around 15-1700. I do plan on a Th200r4 eventually as well, but I'd have to get the floor shift column and cluster from a Regal, as well as a shifter, console, bucket seats, etc. Basically going for a T Type look.

With your GN rear end, 3.42s with a 235/60/15 (standard 15" wheel tire size, don't remember what wheels you were running), and a Th350 you'd be at 2800rpm at 65mph. At 65 you'd be at 1900 with the Th200r4. You could drop it down with a larger tire. But, you already have a TH200r4, and it's kind of a p.i.t.a to swap transmissions. I'd just go with that if I were you.

My memory is a little fuzzy, but did you mention what the Th350 came out of? Is it a short shaft BOP? Lockup? A 455 doesn't need a high stall converter either, but with the lockup feature on the Th200r4 that would permit you to really run whatever you wanted and get decent mpg to boot.

The 350 is the original one for the Regal. Rebuilt a few months prior to doing the frame off.. Was behind the 4.1

 

[MrSony]

The 350 is the original one for the Regal. Rebuilt a few months prior to doing the frame off.. Was behind the 4.1

neat. Yeah, basically just don't thrash on it. Just a standard 10:1 455 will end up having nearly 500ftlbs. And stockpile parts for the Th200r4 swap.

 

[Qdub24]

From my personal experience, and five destroyed TH350s, they don't live long behind that BBB torque without some major internal upgrades.

 

[olds307 and 403]

What year is your car? As long as it isn't a TH250(C).

 

[lilbowtie]

Obviously you don't really want to go into the transmission (which is very simple) With the three upgrades I mentioned it would be a heavy duty - race ready trans. The most neglected thing on the 350 trans is the throttle valve not being set right and I have even seen guys not use them which spells disaster.

 

[Slowpoke]

What year is your car? As long as it isn't a TH250(C).

It's an 83..

 

[olds307 and 403]

If stock it is a TH250C or a TH350C. Make sure there isn't a stud by the cooler connections on the case, that makes it a TH250C, mine lasted one drive with a 8 to 1 Olds 403 but it was not rebuilt.

 

[MrSony]

Obviously you don't really want to go into the transmission (which is very simple) With the three upgrades I mentioned it would be a heavy duty - race ready trans. The most neglected thing on the 350 trans is the throttle valve not being set right and I have even seen guys not use them which spells disaster.

Pretty sure the cable on a Th350 does nothing but kickdown. Hence the slotted cable. If we're talking a Th200, Th250(?), Th200r4, Th700r4, etc then yeah. TV cable =/= kickdown/detent cable.

Apologies if I sound like an *ss.