So I have disassembled a rebuilt 1968 V-8 904 and a toasted 79 slant 904. I want to put the rebuilt V-8 guts in the 79 case. I started to do that tonight. I used the 79 case, 79 output shaft, 68 governor weights, 68 rear sprag gear/overrunning clutch gear, and was going to use the 68 V-8 double wrap low/reverse band drum and gearset.

My first roadblock was discovering that you can't use a double wrap low/reverse band, drum, and gearset in a transmission case originally equipped with a standard solid low/reverse band. So out came the double wrap band, drum, gearset, and rear sprag gear/overrunning clutch gear. Back in went those same 79 components.

At that point I stopped and wondered if I wouldn't be better off finding a 904T form an 80s era truck or van that used the double wrap rear band.

This leads me to my question:

Exactly what 68-up V-8 904 internal parts will fit into a 1979 lockup 904 slant six case?

Can I use the V-8 four gear planetary gearset? Can I use the V-8 clutch packs even if I don't use the double wrap rear band and drum?

Or, would I be better off just ignoring this 1979 transmission and focusing on my near-dead 1973 transmission instead? Bigslantsixfan dissected a 1978 lockup transmission and documented it HERE. Should I grab the 79 output shaft, the 68 five-clutch drum, and the 68 front clutch and put them in the 73 transmission?

I'm trying to build the strongest and most durable transmission for a street driven car possible out of the parts I have on hand. No drag racing, but a reliable daily driver.

Thanks.

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Casually looking for a Clifford hyperpak intake for cheap.

So now that I've been through a good 3 hrs of reading and searching, no answer was turned up. There's plenty on swapping V8 guts into a /6 case ad so forth. Reed being you have a lot of 904 topics I figured I'd resurface this one since it wasn't answered and throw my question in as well. When swapping the V8 guts into the /6 case, can you also swap in the lock up feature? Meaning take v8 904 LU and swap guts plus LU into slant case? As I understand it basically the cases are the difference as the guts swap except for the reverse band (dual and single)

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225, Offenhauser, Holley 350, A833OD, 3:55, GM HEI,99 Durango starter
BOOSTED! WH1C, BIG FMIC, 10#
Operation Noble Eagle 03-05
Operation Iraqi Freedom 05-07
Operation Enduring Freedom 12- 13

That is my understanding as well. Things to watch out for are the 67-68 year spline count and converter snout size change and the reverse band change.

I believe the lockup can be swapped in so long as you swap the valve body.

Other than those few items, all the v-8 guts can be put in a slant six case.

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Casually looking for a Clifford hyperpak intake for cheap.

Great! I stumbled upon a v8 904 at the yard yesterday that was "bad" pretty much already pulled. So ill see if i can get it as a core and use it in a rebuild of one of the two that I got from zilla.
Also there is a slant truck w 727. 1bbl and alum intake, should I pull it the intake just in case? Or whats some things that you would pull?

Ps, look for an FAQ on the 904 next as the FAQ in trans section is a bit thin. Ill do it up like the turbo FAQ i done

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225, Offenhauser, Holley 350, A833OD, 3:55, GM HEI,99 Durango starter
BOOSTED! WH1C, BIG FMIC, 10#
Operation Noble Eagle 03-05
Operation Iraqi Freedom 05-07
Operation Enduring Freedom 12- 13

When I built my one 904 I used the palentaries and the clutch drums from the V8 core. Everything else I used from the slant six case.

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Joshua

Just make sure to keep the internal parts together from whatever trans you use. Specifically I'm talking about where the front planetary fits into the rear (forward drive) clutch, & that clutch fits into the front (direct drive) clutch. Usually I've seen the (male) splined sections that engages the clutch friction discs are different lengths for different number of clutch plates.

For instance, the splined section on the rear clutch housing for a 3 disc front clutch is shorter than one used with a 5 disc clutch.

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63 Valiant Wagon
225 - 4 bbl

I would grab the 727, the carb, and the one barrel intake if you have the time, money, and space. Grab the kick down linkage, the exhaust manifold (if it has the O2 port), the distributor (if it isn't a lean burn unit).

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Casually looking for a Clifford hyperpak intake for cheap.