What would be the optimum trans for a 454?

[spincast375]

My 454 is matched to a TH350. The trans always seems to leak no matter what I do (have replaced the pan gasket several times). I suspect maybe a hair line crack in the case because it is so undersized for the engine. Any suggestions?

What would be the optimum trans for a 454?

 

[sweetk30]

th350 o.k. if built correctly and k case with the brace rods. but th400 was factory behind them. my friend runs th350 in his 454 bigblocks trucks. no problems.

 

[ratzila]

I have used both the sm465 & th400 bolted to the 454. Either one is great.

 

[J.R.]

ive used th350 behind 600 plus hp big blocks with no problems. a well, and proper built 350 will do the job but like you said it may have a crack that is causing the leaks. try adding some dye to the fluid and use a black light to find where the leak is.

 

[sweetk30]

the dye works . any good auto shop like napa will have it. its about 5 bucks or less. and just need a light and glasses just like the a/c system dye uses.

 

[grimjaw]

I love my 4L80e.

 

[85HeartBurb]

I cracked the bell housing on my th350 so i went with a th400 so far so good........

 

[75-K5]

You can never go wrong with a sm465 behind a BBC.

 

[chevy_addict]

For those of you running 454s and SM465s, do (did) you have any issues with the gear splits in the SM465, particularly when towing uphilll?

Dave

 

[Seventy4Blazer]

I love my 4L80e.

my thoughs to the "T"
a 4l80e is the ONLY auto trans in a RWD vehicle i have not blown up. i had my th350 built several times by "one of the best in the area" and i could not keep it alive with a SM350. i had a stock 4l80e behind a 96 vortec 454 with a cam, computer, intake, full exhause and head work. i beat the everlivinghell out of that truck and NEVER once had a problem with the tranny.

oh, other two on my vote since im a manual guy is an SM465/420 OR and NV5600.
Grant

 

[sweetk30]

ya if time and money alow 4l80-e all the way.