8.25 (1/2 Ton) and 9.25 (3/4 & 1-Ton) comparisons.
8.25 is the dirty one, 9.25 is the clean one.
1/2 Ton CV on the top, 3/4 & 1-Ton CV on the bottom.
The 9.25 fits into the 1/2 Ton frame rather easily. it looks to me like grinding off the top ear would be the wrong move since the CV mounting surface touches the frame.
Using the stock upper mounting ear looks to be the correct move.
Unfortunately, this problem arises.
Maybe the right move would be to cut the lower mount off vertically. Then, weld a flat piece of steel on and move the mount to the correct place for the 9.25. One cut, two welds, a little grinding and a custom bar mount on the passenger side and I could have a 9.25 in the front of my truck.
Thoughts on this?
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I remember watching Parish build up his truck before PerformanceTrucks.net split from LS1Tech. IIRC, when Parish went to twins the most power he made was around 1,200 WHP. True, he did race it a lot but IIRC he had some prototype Eaton E-Locker for the 8.25 and ended up having problems with his front end.
if you use stock cv's from GM, I don't believe the 1/2 are any different then 1 ton as I have both and only thing I've found that is different was the inboard hub or plunge hub. If you call Randy, he did a little work to the stock cv's to withstand years and years of abuse with 37's and little failure once he got over the learning curve, I have the Red Racer now and know Randy fairly well....
1/2 ton and 3/4+1-Ton CVs are, in fact, different. The inboard hub is different, as you stated. Also, the shafts are different diameters and the 1/2 ton shaft is longer. I've seen the Red Racer on the internet numerous times! Unfortunately there aren't many good pictures on the net of the front suspension/drivetrain that I have seen.
In the hummer forum there is a thread called "H3 long travel build" have a read through that he did basically the same thing you are asking but used a 44. He built a sub frame to mount the center section to. I doubt your going to be able to squeeze something like that in where your 8.25 lives now but give it a try and let us know.
I saw that before I made this thread. Definately an interesting build.
The 3/4 & 1-ton cv's are a lot bigger than the half-ton stuff. But can't really see the 1/2-ton stuff having problems with the kind of usage the OP is intending.
3/4 & 1-Ton CVs are a lot bigger, like you said. I figure if I'm going to make a custom front end, I might as well make it compatible with the heavy duty stuff.
One of the guys on gmfullsize did the exact swap, but his photos no longer load. I can't remember his name, but PM him if you find the writeup.
I know on the NBS with a knuckle lift swapping CV's is really easy with a mounting bracket, but i know the OBS is a bit trickier.
It absolutely can be done, but it's going to take some really good measurements
Keep us updated b/c a lot of guys have wanted to do a complete 1/2t to 3/4t IFS.
I know that guy (on GMFS) and know of the build. He originally had the RCV CV shafts and broke them. He ended up going back with 1/2 Ton (or maybe it was 3/4 Ton) shafts and hasn't had a problem since.