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I have a 71 C50 w/a 292 L6 I would like to know what 5 speed over drive trans I can bolt in . I work for a scrap yard and stuff floats in all the time . Will anything from a later modeltrucks work ?

Hy MaddMatthew, welcome, tranny choice depends on how hard you intend to work your truck. For example a T5 would be too light duty, an NV4500 might be strong enough for what you intend to do, or any of the older Clark, Spicer, or New Process trannies, if you can find one with overdrive. I'm sure there are other choices out there that I'm unaware of because they are too new, good luck with your search, hope that helps.

NV4500 with Chevy output shaft...'93-'95 Chevy/GMC one ton trucks has .73 OD in 5th gear and will bolt to 292,sb,bb. Look at my pics in "3800"

Also Clark 264ov, 280ov are .80 OD 5 speeds...has to have "OV" in tag.

what year trucks do I need to look at ? we get stuff trickling in all the time at work any of the newer big trucks from 73 to the 90s?

Look at them all until you find something useful or interesting or that you just can't live without, you're there already and so are the trucks right?

Grigg

I haven't found a speed calculator for 10.00 20 tires to see would the final drive ratio would be in 5th. With crude math the .73 ratio should net about the equivalent rear ratio of 4.60ish ?? If this is correct, this swap would be a whole lot less work than a complete rear axle change, although I would still have the split rim wheels I was hoping to to eliminate.
My truck has a '68 engine and bellhousing, so a newer trans should bolt right up.

Try this.
http://www.onlineconversion.com/bigger_tires.htm
OD on a 10.00x20 is about 40" depending on brand and wear.

One can also use ZF 5 and 6 speed trans.' Need to get familiar w/ them first. Direct trans. are more plentiful(NP540 for example) and less cost. One might find a Brownie that would work well w/ either a 4 or 5 speed, direct trans. 5500 and 5800 series Brownies would work fine, there are smaller Brownies too, mainly in farm trucks. Some depends on how hard you wish to work your truck.

I don't see any installed pics. Did you need to modify the floor plate for this conversion ? There are 2 of these within 50 miles of me.

I've been calling about this NV4500 conversion and it is more involved and costly than meerly throwing the trans in the truck. It will not bolt to an older bellhousing. I either need to get the original bellhousing with the trans and convert to hydraulic clutch or get an adaptor bellhousing from Advanced Adaptors for another $405. With a reman price of $1200 for the trans plus the core charge of $350-500, this is getting too expensive....

This adapter plate or make your own version is the simple solution.
http://www.advanceadapters.com/prod...ansmission-to-a-gm-v8-adapter-plate-kit/

I haven't been looking at Dodge transmissions. Are they available with the drum parking brake like a GM ??
No clue what the input diameter is of a stock GM bell either. May need an adaptor ring.

With a GM 4500, stock GM input shaft-Dodges are about 1" longer, one CAN use the original bellhousing. If the retainer dia. isn't 5.125", bore it out; temporarily hold the trans. against the bellhousing, transfer the bellhousing 4 mounting bolt pattern to the front of the trans. Drill and tap the holes in the front of the trans., best done w/ the trans disassembled, but can be done otherwise; make the bottom holes blind or fill w/ epoxy or something, so you don't get a bath when the bolts are removed. The trans. must first be mounted to the bellhousing w/ accessing the mounting bolts through the bottom.
Good luck.

With the Dodge input 1" longer, I see why they can use an adaptor plate. No offense but I'm not interested in a lot of back yard machining. I, and I bet many others, are interested in a simpler, bolt in conversion.

If I can find a Dodge with the e-brake drum assembly, that would be ideal. Otherwise, I suppose the drum could be adapted from a GM tailhousing, but now we're into more parts, cost and labor.

No simple answer here...

I think the simple answer is: there is always going to be a bit of "backyard" machining. Finding a straight bolt in transmission will be quite difficult and if one is considering this type of modification to their truck the one should be prepared to spend the dough and invest the time and effort to do it right. I just installed a Clark and it wasn't an easy task. But it is now functional. Looks good and does everything I ask.

Is your Clark an over drive ?? What was involved with the conversion ??

Discussing this is a way to see what others have done and maybe there is a "simpler" solution.
After talking with several transmission rebuilders/recycling yards over the past few days, the NV4500 swap would best be done with the conversion bellhousing. The Dodge seemed the easier route but none of the rebuilders/recycling yards had ever seen one with a parking brake on the tail shaft. That makes the swap considerably more costly with adding those parts from a GM trans. One may as well use the bellhousing and avoid a total one-off trans. Using the conversion bellhousing also brings another needed modification in that the bell in these trucks was the rear engine/trans mount and the conversion doesn't provide for that. It would be necessary to fabricate a new crossmember mount under the tailshaft of the trans. Most of these conversions require a list of necessary shop equipment that many people just don't own or have at their disposal. Putting collective experience together to research a "bolt in" swap would benefit many...

I found a couple of eatons it looks like it has a roundish bell housing that has an adapter to chevy bell housing also seen a v6 detriot in the pile

Matt, might be a good idea to get a px of the adapter to GM bellhousing-someone might be able to use it.