I have a 454 with a turbo hydra matic transmission. I have searched every where. The tag says 77l 356 and the serial number is 77-cl-2790. If anyone can point me in the right direction please do so. this is a late 70s model engine and transmission with 56,000 original miles. Every thing looks brand new. It come out of a winabago motor home.

 

Man... Screw a bunch of "codes". That's the hard way around. I mean, that's almost like work. Who'd want to do THAT?

Just look at the pan and compare.

http://www.bulkpart.com/Merchant2/me...General-Motors

It's probably a 400.

 

looks like a turbo 700, thank you I have been looking for that info. for a 454 what would be the advantages/disadvantages of a 700 turbo than say a 400..trans?

 

The 700 came out in the 80s, and AFAIK was never used behind a 454. But who knows. It is whatever it is, and that can't be argued with.

The 400 came out in 65, and was used behind 400 CID and larger motors. It's the HOSS transmission. It's a 3-speed with no lockup. The 350 was the little one, it came out in 69, and was used behind everything smaller than 400 CID except in trucks, which got the 400 alot of the time regardless of what motor they had. The larger the truck, the more likely it was to have a 400.

The 700 was the stock auto trans in these cars from 83 up (when it was introduced....). It's a 4-speed, with an OD for 4th; and a torque converter lockup clutch. An altogether more modern transmission. Probably not as "strong" as a 400, but that's probably also not an issue.

The 700 has the advantage of being a direct fit in these cars. Nothing else really is. Although it's not impossible to put the others in, it's just extra work, hassle, and money.

I'd have to see a pic of it before I'd believe that a trans with a '77 date code is a 700, though. For it to be that, the space aliens would have had to take a break from creating crop circles and showing up in Elvis costumes, and visit that vehicle as it rolled down the production line and caused it to be gifted with "features from the future".

 

well since you know what it is why did you give me a site to pick from 30 diferent things? It came out of a motor home 78 model maybe. I know its a late 70s model. thats why i posted this thread for an answer. I just need someone who knows where to find the code info. thank you very much!

 

Post a pic.

 

i cant its still in the motor home allyou can see is the botom. and the flywheel.

 

The bottom is the part you need to post a pic of.

Since the 700 wasn't invented until the 80s, it CANNOT POSSIBLY have come in a 70s anything. That's NOT AT ALL the same as saying that that's not what's there now; since the 700 bolts right up to the motor, and in a truck, it's not that hard to make the other adaptations required. It's entirely possible that somebody did that swap somewhere along the line. Just, not bloody likely.

But we can argue and guess and conjecture and talk about "maybe it's this maybe it's that it's probably something else" from now til Doomsday, and it won't change whatever it IS. It'd just be a waste of bandwidth. Post a pic, showing the pan as clearly as possible; and no doubt I or somebody else will be able to instantly identify it. Also, if you can get a pic of the pass side rear of it, near the back right corner of the pan above the pan rail, that would be helpful too.

 

It will not let me post a pic, can I email it to you ? I talked to the guy and he is the original owner. he said there has never been a swap or anything done at all. I need to email a pic to you so I can show you. But in general thanks for the help.

 

Sure...

 

my email is lulabell4perkins@aol.com on the back of the transmission is clutch/brake, do you know if i can just remove this and install a drive shaft or can it be removed without replacing the tail shaft and the drive shaft?

 

If you click on my name over there on the left, one of your choices will be to send me e-mail.

That's the parking brake IIRC. I think - I'm not completely sure, because it's been awhile since I fiddled with a truck that had that - that it's part of the extension housing, and you can unbolt it and put on a less abnormal ext hsg. I don't think the tailshaft is any different, just the housing. Same for the drive shaft... there were a couple of styles of those used over the years, but you won't be using the truck one anyway. Your existing one might fit, or you might have to get it modified. That would depend to some extent on exactly what the trans turns out to be.