Well I certainly would not chose the 700r4 there would be 0 advanatage its the same trans as the 4l60e except you lose the ability to tune and control shift points. The downsides to the 400 and 350 would be loss of lockup if you run a high stall and of course no overdrive.

 

Yea they blow on the highway unless it's a turbo car. My th400/5k stall and 4.11 runs about 38-4200 at 60-70mph. It is a BEATING!! Normally when I head to the track the truck is pullin 2k and the car 0rpms

 

i drive i95 at 70-75 mph and im at 25-2800 rpm

 

Im pretty sure MPG is not a big concern lol

 

I'm really not looking at the 4L60E or 4L80E due to cost and weight. If I break a 350 or a 400 it would not cost me nearly as much to replace as a 4L60 or 4L80. Yes I know the electronic transmissions have over-drive and that would be nice but my main concern is to get a light weight trans that can handle the power. <---something tells me i'm going to miss having a 6spd.

Do you guys think the power levels that I'm looking at are too much for a TH350?

MPG is not really that big of a concern. I'm not going to use this car for long distances unless it's on a trailer.

 

For the power your going to make, th400, if you spend the cash, you can get lightweight internals, but some say it didn't help. Like I said bud, call up some of the trans shops and talk with them. They won't steer you in the wrong direction.

 

I'm going to assume you'll make an easy 500 HP N/A. Add 300 hit on top of that and you are at 800ish and making a huge torque spike.
I wouldn't recommend a TH350 for that combo, and if "I" were to build one for the combo, it would actually cost more than a TH400 due to upgraded parts necessary to make it live reasonably well. (billet input shaft, drum upgrade, core costs).

A TH400 will be the lowest cost unit you can do that will live.
Depending on options I would say a properly built TH400 for your power level would be about a $1600 unit from me.

That's a TH400 with all our normal build but upgraded to a RMVB transbrake and billet forward hub. Deep aluminum pan standard.
It would be $300 less without the transbrake.

A Powerglide would be about the same cost. That would be a stock case unit.

A TH350 would be around the $2000 mark.

A 4L80E would be about $2850 with a billet input, hub, transbrake.

That should give you some idea of cost for a unit that will live at your level.

 

My comment about driving on the highway at 25-2800 rpm wasn't about mpg, but also not putting less strain on the motor compared at driving at 3500+ at lower speeds. just food for thought.

 

Ya, you're right man. I've already started emailing trans shops to get their input on this. I just wanted to hear from those that already have experience and what they've learned.

The build cost for the TH400 sounds good. As I expected the 4L trans are way more to buildup. I have a guy who is willing to sell me his TH400 for $180. Sounds like a good start to me.

I see what you're saying man. I really won't be driving it on the hwy and if I do it will be very brief. Truthfully, i would prefer the 4th gear but it's just added weight I don't want.

 

What gear/tire and converter do you think you'll run? How much power do you expect out of the engine? I'll chat with my buddy with the 438/ glide and see what he thought about it far as a "driver"

 

LOL at wanting 3rd gear with a glide a glides second gear IS a TH400's third gear.

A glide just a has a lower(numerically) first gear that allows you to throw a ton more power at it out of the hole and not spin as hard or at all due to less gear reduction. If your going to spray it at all especially with that big of a shot on a built 400 cube plus motor and it's a good amount track car over street go with the glide, a taller rear tire(28") and a 3.70-3.90 gear and call it done.

 

$180 is high for a core TH400. My core costs are around $100 for a TH400. If its a good working unit it's worth that but if it's stock it won't live at 800 HP.

The added weight for OD hasn't shown any ET loss for our customers that we've seen.

 

I'm thinking I'll either stick to my current 26x11.5 M/T ET Street bias ply or I might move up to the 28" ET if I really need it.
As for a converter I might go with a mid 3K stall. This way it can see be friendly for the street.
As for the motor...well that's just about anyone's guess but if I had to put a # to it...i'm thinking just north of 700HP at the crank.

What has a higher final gear between the TH400 and the glide? I'm trying to see if I can find all the gear ratios for the TH400 & the glide.

It's not really a core. It's a good working trans. Just something to start out with. I'll probably make a few passes on the motor and see how it feels. If I like it then I'll just have it built.

 

Both high gears are 1:1 and throw that 26 out the door and go to a 28...that engine would give them the once over by it's self let alone on the juice too

 

I was looking HEAVILY into a TH400 for my build. JUST last night I changed my mind and decided hands down to go with a powerglide. After looking around, there is more aftermarket for a glide. Not that there's not a TON for TH400 but... Glide is cheaper to get built stronger. If I want a TH400 to hold 1200whp, I am looking at like over $3k. I can get an off the shelf ATI glide rated for 1500fwhp for $2500.

I was concerned about it only being a two speed and me lacking top end, but both the TH400 and the glide have a final gear of 1:1, so they will both have the same top end.

From what I hear driving around town should be fine. These were transmissions for factory street vehicles before they got turned into race monsters.

Everyone that has a power glide has nothing but good things to say about theirs. I have made up my mind to go with a glide.

 

You do make a good point there man. Not to mention the glide is a lighter trans. My only concern is how it performs at the track. Now I'm still half asleep from a long night, so correct me if I'm wrong... But won't 3 gears allow me to stay in my powerband a longer time? With 3 shorter gears that means that I can get there sooner and stay there longer. With 2 longer gears it will take me a bit longer to get there but I'll only be shifting once compared to 2 times with the 3 spd.

 

Well, you will be at peak torque MORE OFTEN, but it won't stay there longer, it will actually go by quicker. With the glide, you will only be at peak torque twice, but you will stay there longer. It's pretty give and take on that one.

I have no experience on how either one performs over the other at the track. I'm pretty sure they both have their +'s and -'s. I just know that I have been reading and reading. And people that have a glide and are making over 600whp/wtq, love them.

Reason I NOW want a glide is...
Weight (actually less than my 120lb manual I have now)
Size (less hammering out my tranny tunnel, if any)
simplicity (less moving parts to break)
Less mass to turn (Less driveline loss)
Stronger for cheaper
Easier on drive line components out of the hole. (less drive line shock)
Enough torque and you can still have great 60's.
Same 1:1 final drive as any other tranny, so same top speed.

 

Any particular glide I should be looking at? What car or model year? I'm not too family with autos. All my cars have all had T-56s in them. I'm just hoping I don't live to regret going to an auto.

 

After looking around, I wouldn't even bother buying a core. Seems that every place I find sells built powerglides outright. The cost of shipping a core or headache of finding one almost seems to be more trouble than it's worth.

I too am a manual transmission guy. I am in the same boat. Apprehensive about going to an auto. But an auto to hold big power is WAY cheaper than a manual to hold big power.

 

If you guys would like to discuss Glides in great detail I would be happy to talk to you about them. I am a Dealer for ATI and Tranmsission Specialties. Many, many of my clients run Glides in the 4.xx second range.

http://prostockcars.zenfolio.com/p60...dc84#h2a46dc84 That is a link to a car that ran in the Texas Outlaw Pro Mod Assn race last friday night as a matter of fact.

And here's a link to a build I did for another Sponsor back in '98 or so... https://ls1tech.com/forums/automatic...owerglide.html

Holler at me if you have any questions about a powerglide, th400 or any other unit you are considering guys. The best thing you can do for yourself is to become informed before making your purchase!

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