View Poll Results: Trans and rear
TH350/12bolt
15
17.86%
TH350/9inch
11
13.10%
TH400/12bolt
19
22.62%
TH400/9inch
39
46.43%
Voters: 84. You may not vote on this poll
TH350/12bolt VS TH400/9inch
6 & 8 Second Club
Joined: Aug 2006
Posts: 2,284
Likes: 0
From: Illinois, RT 66 dragway area
I went from a 350 to a 400 many years ago because the 350's were breaking and wearing out faster. I was running low 10's. Yes the parts are better now, that's not my point. I ran the exact same ET & MPH. I have heard that 400's have more rotating drag as some have said. But as I said, I ran the exact same.
I went with a 9" for the ease of switching pumpkins. I have 2 so you can change faster if broke. I would always recommend going with 35 spline axles. Most people around here have 35 spline, so you can borrow or sell your center section if needed.
I doubt you will ever need 40 spline like in a Pro car.
I always heard a 12 bolt uses less HP, a dana is very heavy, and a 9" is the best all around, light, easy to work on, strong. Hope it helps.
I went with a 9" for the ease of switching pumpkins. I have 2 so you can change faster if broke. I would always recommend going with 35 spline axles. Most people around here have 35 spline, so you can borrow or sell your center section if needed.
I doubt you will ever need 40 spline like in a Pro car.
I always heard a 12 bolt uses less HP, a dana is very heavy, and a 9" is the best all around, light, easy to work on, strong. Hope it helps.
Originally Posted by mrdragster1970
I went from a 350 to a 400 many years ago because the 350's were breaking and wearing out faster. I was running low 10's. Yes the parts are better now, that's not my point. I ran the exact same ET & MPH. I have heard that 400's have more rotating drag as some have said. But as I said, I ran the exact same.
I went with a 9" for the ease of switching pumpkins. I have 2 so you can change faster if broke. I would always recommend going with 35 spline axles. Most people around here have 35 spline, so you can borrow or sell your center section if needed.
I doubt you will ever need 40 spline like in a Pro car.
I always heard a 12 bolt uses less HP, a dana is very heavy, and a 9" is the best all around, light, easy to work on, strong. Hope it helps.
I went with a 9" for the ease of switching pumpkins. I have 2 so you can change faster if broke. I would always recommend going with 35 spline axles. Most people around here have 35 spline, so you can borrow or sell your center section if needed.
I doubt you will ever need 40 spline like in a Pro car.
I always heard a 12 bolt uses less HP, a dana is very heavy, and a 9" is the best all around, light, easy to work on, strong. Hope it helps.
I started off with my car as a bolt on car, and when I went for a rear gear change, I did the whole 12 bolt, rahter then putting 4.10s' in a 10 bolt... which we all know like ot break. Now the car's got a th400, a stout 402 making the power, and will be seeing nitrous eventually.
I've done alot of stuff that's similar to the fast Eastside nitrous cars, and they were running 12 bolts in most of them, one had a 9 inch. They never had problems with the rear breaking, running setups that were making over 900 rwhp, leaving off a transbrake, that beign said I don't think that a 12 bolt is inadequate, but I don't think a 9 inch is 100% needed either.
As for a dana axle... if you're aiming ot have the heaviest car on the block, then I'd definately put that in.... but only in that case. It may be strong, and all, but the weight, is just too much for any strenth.
If I could do it all over again though for the record, I'd get a fabbed 9 inch with an alum center section.. that's about the same weight as a 10 bolt, and even lighter in some cases..... and strong. Big $, but the best of all worlds really... and if you look at what the weight will cost you in other LW parts, it'[s really no worse then anything else. May still do it someday.
I've done alot of stuff that's similar to the fast Eastside nitrous cars, and they were running 12 bolts in most of them, one had a 9 inch. They never had problems with the rear breaking, running setups that were making over 900 rwhp, leaving off a transbrake, that beign said I don't think that a 12 bolt is inadequate, but I don't think a 9 inch is 100% needed either.
As for a dana axle... if you're aiming ot have the heaviest car on the block, then I'd definately put that in.... but only in that case. It may be strong, and all, but the weight, is just too much for any strenth.
If I could do it all over again though for the record, I'd get a fabbed 9 inch with an alum center section.. that's about the same weight as a 10 bolt, and even lighter in some cases..... and strong. Big $, but the best of all worlds really... and if you look at what the weight will cost you in other LW parts, it'[s really no worse then anything else. May still do it someday.
My 60e just let go after only 15k miles but alot of track abuse. Im researching this very topic not to deciede which way to go. Ive got a 12bolt already and am heavily considering the TH350 now, 4l60e builds are just too expensive to hold any kind of power.
From the sticky:
Weight-
4l80e- wet 255
4l60e- wet 175
TH400- wet 140
TH350- wet 130
Powerglide- wet 110
EDIT: Just noticed how old this thread was..Oops!!
From the sticky:
Weight-
4l80e- wet 255
4l60e- wet 175
TH400- wet 140
TH350- wet 130
Powerglide- wet 110
EDIT: Just noticed how old this thread was..Oops!!
I'm running a th400 with 3000 converter on the transbrake and a 12 bolt with 3.73's. I had a th350 in the car and cracked the case and decided to upgrade. I couldn't tell any difference in the acceleration of the car but it was down for 3 months so I didn't have a back to back comparison. If I was going to do it again I would start with a th400 and a fab 9" from either burkhart or midwest chasis. And if anyone is wanting to convert to a th400 call up Erik and midwest chasis for your mount and driveshaft. I'm really happy with the parts he set me up with to convert
Well we have both combos, a 99Z w/TH400-9" runs 9.90s-10.0s with a 125 shot, 402ci consistant, also a a 98Z with a TH350-12bolt runs 10.48s w/150 shot and a 347ci, both are great combos, you get the ease of the gear change with the 9" over the 12 bolt. I do beleve the TH400 is a bit heavyer along with the 9", either way you wont go wrong.
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