TurboMinivan
Still plays with cars
- Location
- Lehi, UT
(This is not 4x4 related, so that's why I put this thread here.)
As most of you know, I recently picked up this 1980 Grand Prix:
Not long after, I then bought this 1999 Chevy Express 3500 cargo van:
My plan is to remove the 454 and 4L80-E from the van and drop them into the Grand Prix. Muscle car nirvana awaits me.
Of course, there is no way the Pontiac's wimpy 7.5 axle will withstand that kind of torque. I'd probably frag it just dropping the trans into Drive. Clearly, an upgrade is in order... and I've been researching exactly that.
The best option from the factory (read: that totally, completely bolts right in) was the GM 8.5. This axle was used in very few G-body cars (typically only the Grand Nationals and some 442s). As such, they have always been somewhat rare... and nowadays they are practically extinct. Doesn't sound very promising. Even if I did find one, odds are I'd have to lay out a significant sum to acquire it.
Are there any other options? You bet. There is a nice little cottage industry for adapting a Ford 9" axle into a G-body. I can look around the web and find housings which have been modified and are ready to install. Sounds easy enough, right? By the time I have a complete package--the housing made to proper width and ready to install, with axles, a center section, and everything--I'd be spending at least $1500, maybe more. Hmm.
As I've kept digging, I made an interesting discovery. For a G-body axle on a budget, it turns out the Fox-body Mustang's 8.8 is nearly perfect. It is the right width (only 1.0" wider than my 7.5 axle), its outer control arm mounts interface perfectly with the G-body, the inner/upper control arm mounts also do not need modification thanks to an aftermarket adapter kit that attaches new mounts to the body of the car, allowing the kit's adjustable control arms to them make the axle bolt into place. Weld on some coil spring perches and I should be on the road for under a grand, even including the cost of the axle itself. This sounds like the best all-around plan, and it's what I had decided I would do. (You can read more info about this swap here.)
But then my co-worker (who is dropping a very similar 454 into his '64 El Camino) stopped me. Since I need to find and buy an 8.8 axle, why not just use what I have? Namely, the axle in the van. "Be like the native Americans," he says, "and use every part of the buffalo."
So the other day I drove down to Orem to crawl under the van and see what is there. Here is what looked back at me:
It's a GM 10.5" 14-bolt. On the plus side, it's a one-ton axle that can certainly stand up to whatever amount of torque I throw at it. As another bonus, I already own the thing. And one more benefit is I already own the driveshaft that attaches both to it and the transmission I will use; I'll just have to have it shortened. From a parts cost standpoint, it sounds like a fabulous idea.
But then there is the not insignificant matter of making it fit under the Grand Prix. All the OEM spring and shock mounts will need to be removed, then I'll have to graft in the appropriate equivalents for the car. Oh, and I'll most definitely need to have the housing narrowed to the correct width and have new ends precision welded as required. Then there will be the new custom-length axle shafts, and who knows what else.
Now I know there are many RME members who can do (and have done) this sort of thing in their 4x4 rigs. Converting to a stronger axle is a decades-old experience in our hobby. But here is my question to you who have done such a conversion: is this a better overall move for me? Would it be worth all the added work and effort to convert what I already have on hand? Or does it make more sense to go out, buy a different used axle, and then take the path of easier fabrication? Do any of you think the GM 14-bolt route would actually end up saving money compared to using a Ford 8.8? (Keep in mind that I do not have the tools or knowledge to do this sort of fabrication, so I'd be paying someone to do it... maybe even somebody on this forum.)
I welcome all thoughts, comments, questions, snide remarks, etc.
As most of you know, I recently picked up this 1980 Grand Prix:
Not long after, I then bought this 1999 Chevy Express 3500 cargo van:
My plan is to remove the 454 and 4L80-E from the van and drop them into the Grand Prix. Muscle car nirvana awaits me.
Of course, there is no way the Pontiac's wimpy 7.5 axle will withstand that kind of torque. I'd probably frag it just dropping the trans into Drive. Clearly, an upgrade is in order... and I've been researching exactly that.
The best option from the factory (read: that totally, completely bolts right in) was the GM 8.5. This axle was used in very few G-body cars (typically only the Grand Nationals and some 442s). As such, they have always been somewhat rare... and nowadays they are practically extinct. Doesn't sound very promising. Even if I did find one, odds are I'd have to lay out a significant sum to acquire it.
Are there any other options? You bet. There is a nice little cottage industry for adapting a Ford 9" axle into a G-body. I can look around the web and find housings which have been modified and are ready to install. Sounds easy enough, right? By the time I have a complete package--the housing made to proper width and ready to install, with axles, a center section, and everything--I'd be spending at least $1500, maybe more. Hmm.
As I've kept digging, I made an interesting discovery. For a G-body axle on a budget, it turns out the Fox-body Mustang's 8.8 is nearly perfect. It is the right width (only 1.0" wider than my 7.5 axle), its outer control arm mounts interface perfectly with the G-body, the inner/upper control arm mounts also do not need modification thanks to an aftermarket adapter kit that attaches new mounts to the body of the car, allowing the kit's adjustable control arms to them make the axle bolt into place. Weld on some coil spring perches and I should be on the road for under a grand, even including the cost of the axle itself. This sounds like the best all-around plan, and it's what I had decided I would do. (You can read more info about this swap here.)
But then my co-worker (who is dropping a very similar 454 into his '64 El Camino) stopped me. Since I need to find and buy an 8.8 axle, why not just use what I have? Namely, the axle in the van. "Be like the native Americans," he says, "and use every part of the buffalo."
So the other day I drove down to Orem to crawl under the van and see what is there. Here is what looked back at me:
It's a GM 10.5" 14-bolt. On the plus side, it's a one-ton axle that can certainly stand up to whatever amount of torque I throw at it. As another bonus, I already own the thing. And one more benefit is I already own the driveshaft that attaches both to it and the transmission I will use; I'll just have to have it shortened. From a parts cost standpoint, it sounds like a fabulous idea.
But then there is the not insignificant matter of making it fit under the Grand Prix. All the OEM spring and shock mounts will need to be removed, then I'll have to graft in the appropriate equivalents for the car. Oh, and I'll most definitely need to have the housing narrowed to the correct width and have new ends precision welded as required. Then there will be the new custom-length axle shafts, and who knows what else.
Now I know there are many RME members who can do (and have done) this sort of thing in their 4x4 rigs. Converting to a stronger axle is a decades-old experience in our hobby. But here is my question to you who have done such a conversion: is this a better overall move for me? Would it be worth all the added work and effort to convert what I already have on hand? Or does it make more sense to go out, buy a different used axle, and then take the path of easier fabrication? Do any of you think the GM 14-bolt route would actually end up saving money compared to using a Ford 8.8? (Keep in mind that I do not have the tools or knowledge to do this sort of fabrication, so I'd be paying someone to do it... maybe even somebody on this forum.)
I welcome all thoughts, comments, questions, snide remarks, etc.
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