Thread: 7/8" chain vs GMR 1"

i have a built tranny. i need to replace my tc, as i think it is shot. i am going from a 2750 to to a 3000 and adding the meziere flex plate.
i currently have a set of stage 3 heads being machined and am going with an xpz or something big along those lines.

Question:
do you think the 7/8" chain will hold the extra hp or should i bump up the chain to the GMR 1" while i have the tranny out? Or will it last me a little while? I have the money to get the bigger chain, but would like to spend it on a few other items like an elec water pump and a new alum radiator along with a few other items.

lmk ur thoughts...

What kind of times have you / do you plan to run with the car? How many miles are on the trans since it was built? The 7/8" chain will handle plenty of power but like any other chain it will stretch over time. Do you plan to use slicks on the car often? Since the trans will be out it wouldnt hurt to tear into it to check for chain stretch if you have a few miles racked up on it and have had a lot of track runs with it. If you are planning on running at least low 11s or faster with slicks and lots of track time then I would consider the 1" chain so you dont have to worry about it.

i have been running low 13's and i have about 35k on the tranny. i have only been to the track a hand full of times since the rebuild and have ran drag radials the last two trips to the track with a total of maybe 15 passes with the drag radials. i do plan on running full slicks and i am hoping to run mid to low 11's.

that's what i thought you would say. i was just hoping to buy a few more go fast parts. o well, the other go fast parts are a lot easier to install over the chain and gears...

One of these days someone is going to have to explain to me how a chain, made of metal, stretches that much. Im just having a hard time getting my head around that one.

These transmissions have it easy! Back in the mid 60s when the REALLY heavy cars, Riviera and the Toronado and Eldo had 455 big blocks churning power through a chain drive since they too were fwd cars.

I have the same question. Where do you get the gears and 1" chain from? I don't see anybody that sells it. I have also google searched it.

Also, is it possible that the 1" chain will fit the 95 Rivera Rocker type gears?

The 1" chain ONLY fits custom made gears, not the 4T60E gears like the 7/8" chain. Mike from W-Body Store can get the gears I believe, we have talked a little about them in the past so he may be a good source to ask.

i believe you can get it from dynotech

Originally Posted by my97gtp

Ive always been the opposite. I was always amazed a chain so small could move that much mass and transfer power.

x2, I couldn't believe that there was chain in a transmission when I read it for the first time. Why couldn't they use gears instead of a chain.

Because of the layout of the trans a chain is probably the easiest/best route to go. If they used gears they would have to orient them to be quiet and keep rotation the same, as well as add a lot of structural support between the two gears. Also there are fluid passages right in the way of where gears would go and this would also cost a few bolt down locations for the channel plate and valve body. I always thougth a geardrive setup would be the ticket and would eliminate all chain issues but there is really no easy way to do this durably in the existing case. They have been using chains for over 40 years in fwd transmissions and if it was a big enough strength issue I think GM would have worked around it. Ford also uses a chain in their fwd transmissions. Near everyone else uses gear driven internals so there is no chain to worry about.

i ordered my 1" chain set last week from DynoTech:

Dynotech Performance - Hi-Pro Transmissions