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Hey guys--

I currently have a 66 C4 with the matching valve body. I am debating switching valve bodies because the current one does not allow the car to be held in second gear. Does the 68 and up valve body allow the car to be held in 1st and 2nd, or just 1st? Is that valve body completely interchangable with the older style C4.

Also, I am not able to get the C4 to hold the gears much past 4400 unless I hold it in there manually (1st only). I have tried adjusting the modulator, but that didn't work at all, only made the shift quality crappy. I am running the C4 behind my 331, with a 2400 rpm converter in there. The engine should be able to wind up to about 6500 without any problems at all, and I have hit around 5500-6000 holding it in manually. Is there any way to convince the tranny to stay in the gears longer without manually holding it there?

Thanks
Dave
 
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Sorry I can't help you with your valve body question Dave, but I'm so bored at work. 3/4 of the shop on vacation you know? Remember that C4 & C6's were built to shift manually. I'd like to think of mine as a poor mans 4-speed; easier to maintain and you never miss a shift.
 

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The 67 and later valve body has the 1-2-D pattern you want. That's what I have in my 66 C4. I can manually hold it in gear as fast as I want to spin it.
 

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Does the 68 and up valve body allow the car to be held in 1st and 2nd, or just 1st? Is that valve body completely interchangable with the older style C4.

IME, I know the '67 valve body interchanges and, with a manual/automatic shift kit, it does hold the gears when shifted manually.

I achieved the same thing in the early valve body in the race car by installing a full manual, straight pattern shift kit...it eliminated automatic operation and boosted internal pressures to help handle the stresses of shifting at the race track.

With your stroker, I'd recommend putting a shift kit in the 67-up valve body to firm up shifts and help the trans last longer....

Good luck!
 
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