Selecting a Transmission

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Jul 30, 2003 | 12:19 PM

my79f

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Laughing Gas

Joined: Jun 2003

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Selecting a Transmission

the deal is im switching the motor out from a 300 inline six to a 302 stroked to 347 with around 320 to 400 horsepower and right now i have a four speed transmission in it but i want something that can stand the horsepower range. So i was thinking about going with the tremec tko or the 3550 five speeds, or a beefed up c6 or c4. plus i want good gas mileage, but also want to have gears rated more for the dragracing side.

Thanks,
Austin

p.s. the truck is a 1979 f150 4x2 long box

Jul 30, 2003 | 05:31 PM

Matts72

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From: Montana Territory

Selecting a Transmission

I don't believe the TKO has an OD and since its built for higher HP applications I would scratch that one off your list.

I don't know what a 3550 is.

I don't know what the gearing of the C4 is but I have one behind a 351C and it has held up for 30K miles, definetly a worthy option.

Finding a C6 with the small block ford bellhousing is difficult but another guy here is having one recased and that might be a worthy option. I would ask him how to go about it. Gearvendors has a nice OD unit for the C6. We have a C6 thats been in service since 1974 and its got 360,000 + miles on it.

I don't really think the 347 is such a good idea either. I have heard that its not as driveable as a 336 or even a supercharged 302. Just another route.

Jul 30, 2003 | 06:21 PM

classic79

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Joined: Jun 2001

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From: Alabama

Selecting a Transmission

The 3550 should work, but to be safe with the weight I would go with the TKO or a c-4.

Jul 30, 2003 | 08:25 PM

Torque1st

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Selecting a Transmission

A C6 behind a 300-6 with the small bellhousing was a common option in many E150/250/350 delivery vans. Not hard to find at all.

Jul 30, 2003 | 08:50 PM

my79f

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Laughing Gas

Joined: Jun 2003

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Selecting a Transmission

so where would i be able to find a new c6 or c4. and out of both of them which would be able to hold up the longest and which could take the most hp

Jul 30, 2003 | 11:32 PM

Matts72

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From: Montana Territory

Selecting a Transmission

Lots of auto stores have rebuilt trannies and I suppose you could buy a new one but a junkyard is gonna have that tranny and it will only be about $200.

Jul 31, 2003 | 01:10 AM

Torque1st

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Selecting a Transmission

The C6 is far stronger than a C4. It is also bigger and heavier. They put the C6 behind 460's and diesels. AFAIK the AOD is based on the C4. The AOD can be built to take tremendous power levels. You can get high performance AOD's from Jegs or Summit.

I would go with an AOD behind your motor.