If the only difference between the standard and Heavy Duty transmission is the differential and TQ converter (plus inner tulip on axle side).

Would it make sense to convert a non HD one? I ask because two reason's I have a Getrag that my friend want's to swap into his 3800. And he has a 4T65e that I want. EXCEPT I want to add power to the 3800sc when I complete the swap and want a HD type of transmission. So can I find the TQ converter and differental? Then put in HD axles.

Or is it smarter to just find a 4T65eHD tranny from the get go?

Other reason I ask is because we are coming across alot of 3800sc engines at Junkyards but with the standard non HD transmission.

Thoughts anyone?

If you think you will want the HD someday and you have not yet installed the 65e yet then why not go with the HD to begin with? I don't know how much of an issue it is to get a hold of one so that might make the difference for you.

Charlie

Like I had said. We have come across 3 3800sc engines and tranny all-non HD. In all of the San Diego junkyards their are no HD trannsmissions to be found. We have been waiting for month's to try and find one. Maybe I should look out of state, I don't know.

What I do know is that my friend has a 4T65e transmission he will give me for free. Free is good. That is the #1 reason I posted the question. I want to put around 400rwhp with this engine and need to HD type transmission to adequately do that.

Ooops, my bad, I interpreted your question as converting a car from 65e to HD not converting the 65e to a HD. Can't be of any help there.

Charlie

quote Originally posted by blkpearl: If the only difference between the standard and Heavy Duty transmission is the differential and TQ converter (plus inner tulip on axle side). Would it make sense to convert a non HD one? I ask because two reason's I have a Getrag that my friend want's to swap into his 3800. And he has a 4T65e that I want. EXCEPT I want to add power to the 3800sc when I complete the swap and want a HD type of transmission. So can I find the TQ converter and differental? Then put in HD axles. Or is it smarter to just find a 4T65eHD tranny from the get go? Other reason I ask is because we are coming across alot of 3800sc engines at Junkyards but with the standard non HD transmission. Thoughts anyone?

If the motor is a 3800Sc then the trans should be the HD version as they never came with a non HD from the factory. Of course someone could have swapped it out down the road but not on all of them. How are you deciding that they are all non-HD transmissions?

On your question....I think a non HD in a Fiero swap will hold quite a bit before giving up the ghost. Unlike the donor cars the Fiero is much lighter and puts alot less stress on the trans..

Edit: I think you will be fine with a non HD trans for the HP level you are looking for....Going to be hard to get 400 HP and make Cali happy at the same time...

[This message has been edited by MstangsBware (edited 07-03-2010).]

Yeah Cali won't be happy and they can kiss my arse. But that is another discussion. I will mod the motor after it's cleaned up.


He says his tranny is the 4T65e.

I have an option of getting a Buick Regal with the SC motor for really cheap. Does this come with the 4T65eHD? Or is that tranny only in the Bonneville ssei's and Grand Prix GTP.

I know myself and will want to do burnouts, quarter miles, Willow springs with this setup. I want the transmission to hold up to this kind of spirited driving. Car weigh's about 2650 lbs. Lighter than stock for an 88. It's stripped is the reason why.

I agree with mustang beware. You should be fine with a non hd trans everything I have read suggest a fiero with a on hd trans will be fine because they are much lighter than the cars that came with the L67 setup.

[This message has been edited by Blue87Fiero (edited 07-03-2010).]

quote Originally posted by blkpearl: Yeah Cali won't be happy and they can kiss my arse. But that is another discussion. I will mod the motor after it's cleaned up. He says his tranny is the 4T65e. I have an option of getting a Buick Regal with the SC motor for really cheap. Does this come with the 4T65eHD? Or is that tranny only in the Bonneville ssei's and Grand Prix GTP. I know myself and will want to do burnouts, quarter miles, Willow springs with this setup. I want the transmission to hold up to this kind of spirited driving. Car weigh's about 2650 lbs. Lighter than stock for an 88. It's stripped is the reason why.

The best way to tell if the tranny is an HD version is by running the code of the tag on the tranny....If the trans is attached to a SC motor then it will be a HD trans unless is was changed out sometime in it's life by someone. Yes the Buick Regal with 3800SC motor has the HD trans....


The 96 Buicks with SC motors even came with an HD trans but it was the 60 HD.

Hate to be a salesman, but I have a 4T65e-HD with less than 10k miles on it for sale. PM me if interested. Comes with everything including mounts to put it into a Fiero.

------------------
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[This message has been edited by MadDanceSkillz (edited 07-03-2010).]

11.42@115.x MPH here with 4T65E out of a montana van. The HD diff makes the passenger axle more of a pain in the ass I think. As long as you spin both tires, I don't think there are too many problems with the standard diff. If you spin one tire, the spider gears will weld to the shaft, break the roll pin, and then destroy the diff, but this will happen HD or non-HD. I personally wouldn't bother with converting to the HD diff, just get a decent convertor with a bit more stall and put the trans in. If you are looking to make 300+ hp, then a aftermarket input shaft and drive chain setup would be a good idea. Another bonus of the standard 4T65 is the 3.29 gearing rather than the 2.93 in the HD version.

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11.425 @115.60
Best 60' 1.543 seconds
3800 S/C 4T65E

Blk Pearl, to be honest, I dont know if it is a hd or non-hd. I was just told if it came out of the 1998 riviera, it was non. That person could have be wrong. Maybe someone can help me. How can I tell if it HD or not?

[This message has been edited by iluvsd619 (edited 07-05-2010).]

quote Originally posted by iluvsd619: what code am i looking for and where is it on the tranny?

There is a metal tag on the tran with numbers on it. Look on Darths site to decode what the tran came from and year.

Thanks, I saw the site, but it doesn't tell me if its HD. I want to assume that since it has the 258mm TQ converter on all the cars with the SC motor, that it is an HD.

If the motor is SC'd it is the HD trans.

I would probably prefer the non HD versions myself. You get a better converter and a easier pass side axle setup.

Cool. Its an HD then.