'72 Chevy 3/4 ton 6.2 conversion

[turbotim]

I'm making plans to put my old Custom/20 flatbed back on the road that has a 4 speed manual trans and a Dana 60 rear. I'm considering picking up one of the 6.2L mechanical military take-out engines that are out there to replace the 350 and I was wondering if anyone who's tried something like this could tell me what I'd need to do this & if I'd be better off with a donor vehicle that has a running 6.2L instead... /// tim


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1998 VW TDI 190K d/d 47mpg
1995 C3500 HD dually 6.5L TD (project)
1972 C20 3/4 ton
1948 Farmall H

[More Power]

Welcome to the board! The following thread here in the "Diesel Conversion" forum hits the high points for such a conversion.

http://www.thedieselpageforums.com/t...ad.php?t=27827

Jim

[turbotim]

Thanks for the welcome, Jim!
I read the thread you mentioned and my 6.5L books arrived along with my Helm manuals for the 3500 HD, so I have plenty of reading to do to prepare for my 2 projects. I was out disconnecting everything from the 6.5L in the 3500 so I can pull that one out over the weekend with some help.
The 72 3/4 ton has a manual trans, so if I understand I should be able to bolt up to it, but I'm wondering if I have to make any changes to the existing gear ratio on the Dana 60 or if I'll be o.k. keeping everything the same as it was with the 350. I know this is an older vehicle than usually is used for such a project, so I'll keep reading though some of the older posts to find any more information on a similar switch done by someone already.
I'm sure I'll learn quickly with all of the information that I now have available to me, and look forward to being a member of this group. /// tim

[catalina291]

Hi I bought a 1970 Chevy that a guy was trying to convert over from a 350 gas to a 6.2L diesel. He did not have much experence with this kind of project, so I picked it up. Anyway the engine was out of a 1984 K5 Blazer, and he tryed to use the engine frame mounts from the Blazer, this put the engine to low. I put the frame mounts from the 350 back in, this didn't work ether. The exhaust manifolds hit the mounts, so I had to get the frame mounts from a Big Block I used the engine pads from a 350 gas and this worked out good, hope this helps. John

[67-72williso]

I gess i`m in the right area. I`m working on a 6.5TD in a "72" K-20. right now I`m tring to figure where to set the motor front to back.
Willis

[JeepSJ]

I gess i`m in the right area. I`m working on a 6.5TD in a "72" K-20. right now I`m tring to figure where to set the motor front to back.
Willis

Use the big-block frame mounts in the stock location.

[67-72williso]

Turbotim, the best gear you can get in a Dana 60 is 3.33 for diesel non OD trans applacation.
Later, Willis

[67-72williso]

JeepSJ
I am using engine crossmember out of a "87" 6.2 diesel truck. It`s a little different mix of things. The turbo is on the back on this one to (van type).
Thanks, Willis

[JeepSJ]

JeepSJ
I am using engine crossmember out of a "87" 6.2 diesel truck. It`s a little different mix of things. The turbo is on the back on this one to (van type).
Thanks, Willis

I gotta ask - why are you swapping crossmembers? The 6.2/6.5 share the same engine mounting locations as the small block and big block gas engines, so it would have bolted right into the original crossmember. What are you hoping to gain by swapping the crossmember?

[67-72williso]

JeepSJ
In 67-72 4X4 there were no BB installed the oil pan hits the crossmember. In 2 WD they used them in these years. So buy using 73-87 4X4 crossmember that should make that part work. I also put the front swaybar crossmember in to.
Willis

[Burning Oil]

I ran into the front xmember hitting also on mine. A 1970 4x4. You are correct that they never came with a big block in the 4x4 in that body. I did put one (454) in mine and I used the xmember out of a 1974 4x4. I had to nocth it and reinforce it at the harmonic balancer or it would hit. Also I had to modifiy the fire wall. Not sure if these problems will pertain to the 6.5/6.2

[67-72williso]

Burning Oil
I understand the cutting of the firewall, because you didn`t move the BB mounting front to the the 2WD position. But I don`t see why you had to cut the crossmember if you used all the 73-up clamshell motor mount stuff.
Thanks, Willis

[Burning Oil]

I did this 5 or 6 years ago so I don't remember exactly now, but I think thats just the way it worked out. I do still have the truck and could take some pictures if it will help.
Later