New here

[Jeff's72C10*]

Hi all, recently picked up my 3rd 67-72 pu.

I purchased a 72 LB Custom Deluxe (pic in avatar). Truck has a 350 4bbl, TH350 tranny and factory air (currently inop). Question I have is how much trouble would it be to swap the TH350 for a 400? Brackets, braces etc. The last 2 I had (69SB & 72 Cheyenne LB) had the 400 transmission. Is it worth it to swap or just leave as is. Thx in advance.

[jocko]

I'd leave as is with a 350 eng personally. If you soup it up, maybe worth an upgrade, but if you're going to spend the $ on an upgrade, recommend a beefed up overdrive trans for lower highway rpm, unless you currently have a 3.07 in the back - in which case it may not really be necessary. For a driver that you aren't doing burnouts in (IF you aren't doing burnouts in it, that is ), a TH350 is a sound, reliable trans, not worth the effort to swap in my opinion. If you are doing burnouts, I'd still wait, if it fails, then that means it's time for a swap - so, maybe I should say it's not worth it to pre-emptively swap it as it may not be necessary.

[Jeff's72C10*]

Originally Posted by jocko

I'd leave as is with a 350 eng personally. If you soup it up, maybe worth an upgrade, but if you're going to spend the $ on an upgrade, recommend a beefed up overdrive trans for lower highway rpm, unless you currently have a 3.07 in the back - in which case it may not really be necessary. For a driver that you aren't doing burnouts in (IF you aren't doing burnouts in it, that is ), a TH350 is a sound, reliable trans, not worth the effort to swap in my opinion. If you are doing burnouts, I'd still wait, if it fails, then that means it's time for a swap - so, maybe I should say it's not worth it to pre-emptively swap it as it may not be necessary.

Thanks you sir for the info. It does have a 12 bolt rear end but not sure what gears. Some one through the years was kind enough to put a chrome glove box door on, so no SPID.

[truckster]

I've run a TH350 behind a built Olds 455. They're plenty stout, and they have less drag than the TH400. I see no reason to change it.

Oh, I forgot to say... Welcome to the board!

[Coley]

To my understanding the fuel mileage with a TH400 will drop off as well.
I think this is due to the fact that they take more hp to run perhaps.....if that matters?

Regardless tho', like the guys said....I'd stick the TH350..its a great transmission, tough and well suited to these trucks in a 1/2 ton with the 350.

just my two cents.

Coley

[Jeff's72C10*]

Originally Posted by Coley

To my understanding the fuel mileage with a TH400 will drop off as well.
I think this is due to the fact that they take more hp to run perhaps.....if that matters?

Regardless tho', like the guys said....I'd stick the TH350..its a great transmission, tough and well suited to these trucks in a 1/2 ton with the 350.

just my two cents.

Coley

Appreciate all the input guys. Thank you