Just a quick question that maybe a few of you can answer, what kind of time and mph could I expect to pick up, going from a th400 to a th350? Right now the cars is running 13.8's @95. There are some changes in the works for the winter, I am just wondering if the engine were to remain the same and only change the trans what kind of differences would I notice?

if you only have enough power to get a 13.8 then I wouldn't imagine it would be enough of a difference to matter, maybe 13.7 or so....the equivalent of 14hp difference. Not worth it at all in my opinion.

You should pick up a little.

The TH350 has a slightly better gear ratio. It doesn't eat up as much HP and it doesn't weigh as much.

i still don't believe it's worth the added expense of swapping trans, when that cash could go to different parts that will actually make the car faster, unless you plan on selling the TH400 and buying a TH350 and have cash leftover. Sounds like you need a plan of attack to get better times for what you're looking for.

You'll want the th400 for later if/when you build a big hp motor.

If this is a track only car put powerglide in. Much more consistant than a turbo 350 or 400. With a 4000 stall converter, 1.82 glide and 4.10 gears should put you in the low 13s

i would keep the th400 and do some motor work.

I have 2 spare TH350's setting in the garage that is why I was wondering. As far as the PG goes, wouldn't it slow me down due to the weight of the car? Even with the 4.10's? I am planning on stepping up the lil' 305 this winter to pick up a little more HP, and was just wondering wether or not to swap out trans as well. The 400 will stay around as the big motor is on the stand and should work well with it, I just hate not having reverse due to the Turbo Action vavle body that is in it.

if you're planning on doing more motor stuff, i'd suggest swapping to the cam i'm running. 238*/248* .480"/.500" 114lsa solid cam from Crane. i want to see that car go fast just as badly as you do. i don't think going to a th350 is going to help either. a PG would be the worst thing you could do for this type of car...my pops has one in his car and we keep contemplating a th350 or th400 for it.

oh, and i'm keeping my 305! crane is going to replace my cam and i've worked a deal with my machine shop to do up my spare 416's!

ok kwik, i went and looked over a few of our old posts and here's what i think you need to do:

-keep your th400 and 3500 stall
-put a 4.10 gear in the car OR go down to a 26" tall tire
-ditch the xceleratot intake and run a holley street dominator intake p/n 300-36, this intake makes MUCH more power all the way around. the technology in todays dual plane intakes are much better than they used to be and will help build much more torque, which you lack.
-put some sort of exhaust system on the car to help control velocity. open headers are killing you.
-the crane solid lifter cam i suggested, but even if you kept your current camshaft, the above would help TREMENDOUSLY. the camshaft you're currently running is NOT a high rpm hp building cam, it's more of a street/strip cam with lower end torque in mind, but not having a dual plane intake and exhaust system is making building torque difficult. so the combo is a bit mismatched. i've been racking my brain all summer long trying to figure out why you've had so many problems getting this thing to run right. and i think it's boiled down to just a mismatched combo. putting the dual plane intake and exhaust system on (we're not talking anything special, hedman x-tensions with bullet mufflers dumped before the rearend.) would be super beneficial to help add torque. consequently, the car would also become more streetable...which is always a cool thing.

I have been thinking about a few of those things as well. I am switching cams this winter a hyd grind 234/244 with .488/.510 on a 114 lsa. Switching to a rpm intake. The heads are going to get some work done to them as well just not sure which set yet. I've got a pair with 1.94, and a pair with 1.84. Gear is getting changed as well, prolly 4.10, but also kicking around the idea of a 4.56 gear as well. Header extensions are on the schedule as well. Car is going on a little bit more of a diet over the winter as well, looking to remove another 50 or so out of it. No worry about steetable that passed a long time ago.

I've got a spare th350 if your interested, does need a rebuild though.

LONG LIVE THE 305!!!!!!

well, i'll be putting a set of 416's back on with the stock 1.84" intake valve, but i'm having them backcut, so i'll get you some results as soon as i get them back on the car.

i'm running quite the 700r4 in my car right now, but i'll be in the market for a th350 that put a brake in and stuff later on...oh...you meant for my pops car...yeah, that's just a thought that keeps gettin' kicked around, we'll see if that ever actually happens...you can pm me a price either way though!