Introducing New Member: NorthernNYMOPAR

[NorthernNYMOPAR]

First time here, long time MOPAR guy...Dusters, Neons, Daytonas, Diplomats, Trucks, 'Cuda, etc.

Location: Adams, NY

 

[Joe12459]

Welcome aboard! Any pics?

 

[NorthernNYMOPAR]

I would guess most interested in my F-M-J pictures?

 

[NorthernNYMOPAR]

My latest endeavor, and what has drawn me here is an f-body bracket drag car, I dragged a few times, then started on some circle track stuff, then started supporting the wife's racing habit and kids got in the way and we been circle tracking. That seems like a dying sport honestly especially at the asphalt street stock level, so decided at this point to use some of my stored up inventory and build a mild build bracket car. I bought a major project / parts car then a second more logical builder (which will utilize car 1 to bring to fruition) so here is the first purchase.

 

[NorthernNYMOPAR]

And here is the car that will become the bracket car.

 

[BudW]

Welcome aboard!

We enjoy pictures of all cars here (and I have owned a lot of the same ones, myself).

I like this picture. It reminds me of a Craigslist sales ad of a rust free car (because the seller cut out all of the rust . . .).
BudW

 

[NorthernNYMOPAR]

This one became a parts car for his other which apparently had a nicer shell but really bad floors, I will use what I can for parts from it, not much, but there were a few gems, the hooker headers and Holley electric fuel pump, the rear end turned out to be not so much it was supposedly dragged and has a suregrip but is the 2.26?? Ratio, so got my money out of it, not sure what will happen with the rest of the shell (for now it sits with my other parts cars), my feeling is best to go to a circle track guy

 

[BudW]

Not very many F-bodies (if any) got a 2.2 rear differential (7¼” or 8¼”).
With that said, most of the M-bodies (85% plus) did get the 2.2 ratio rear differential (7¼” or 8¼”). I suspect that might not be the original rear differential for this car.

Before doing with the blue (or black) body, before to remove the wheel well trim! Those pieces are hard to find.
BudW

 

[NorthernNYMOPAR]

Yeah imagine that a non-original rear in an almost 40 year old car that was drag raced, I suspect someone may have yanked the rear that was raced and threw this one in, or hw did race it like this, either way not much use to me, can't put any decent gear on it and if I'm going to throw much money at it going to upgrade it probably go 8 3/4 and thanks for the heads up on the trim.

 

[NorthernNYMOPAR]

Not very many F-bodies (if any) got a 2.2 rear differential (7¼” or 8¼”).
With that said, most of the M-bodies (85% plus) did get the 2.2 ratio rear differential (7¼” or 8¼”). I suspect that might not be the original rear differential for this car.
BudW

I think I have confirmed your suspicion, I now have the rear out (of blackish car) and put it under the grey car, it appears wider and sure enough measures about 60.5" overall (drum to drum) and I seem to remember F's being around 58.5"(didn't measure perches but they seemed right, set right in) this isn't my final rear I was going to go 8 3/4 which I have and came out of an e-body so it is roughly the same 60.5" which I think will be fine for what I am doing. (knowing I will be moving spring perches)

 

[BudW]

The chart below is one of the most correct ones I have ran across – and it is far from complete. I have pages of additional and updated information. Also I have a lot of information on newer vehicles to add to it (one of these days . . .). The green cells are data I’m missing or not 100% sure is correct.

When done, this spreadsheet will be about twice the size (or more).

FMJ-body perches are 44.46” center to center. 65-70 B-body perches are 44” center to center. Most leaf springs will "give" ¼” per side to fit in.
Pretty much all other differentials will need modifications to fit (perches cut off and added, width, etc.). Technically, an earlier B-body Dana 60 will bolt right in.

Drum to Drum as well as Flange to Flange measurements are not easy to make, solo.
BudW

 

[NorthernNYMOPAR]

I cheated lol, I had the brake drums off and c-clamped a piece of angle iron onto the axle drive flange face so I then had a damn hand place to hook tape measure and avoid everything so I could get a straight shot. Because it is mainly a drag car not so worried about widths so if tires stick put oh well it gets that 70's look. I also thought I remember some oddity that isn't shown in any chart I've looked at like the later M-body axles were an inch or more wider than the F. I think my plan to just use the e-body 8 3/4 I got, move the perches and wherever the tires fall so be it.

Thanks for the additional charts.

 

[BudW]

All F-body, M-body and J-body differentials have the same differential width and will interchange with each other in the FMJ-body camp – including the 7¼” and 8¼” – except for driveshaft length is slightly different, and some early F-body 7¼” differentials have different tube diameters (which means the U-bolts and the leaf spring clamps are different on them).
The Late ‘70’s 7¼” differentials have larger tubes thereby sharing the 8¼” U-bolts and spring clamps (Iso-Clamp).
I hadn't seen a small tube 7¼” in a long long time.
BudW

 

[NorthernNYMOPAR]

You are testing my memory now, it has been 25+ years since I went through this last time, and time and miles may have taken a toll on my memory, I'll have to see if I have notes, but I do swear that when I swapped out a 1978 F body (Volare wagon)and put in a 80's M (cop car Diplomat? (It had a suregrip with a livable and swappable ratio of 2.76) and I swear it was live about an inch wider but memories aren't always accurate, so, I'll look. Thanks

 

[NorthernNYMOPAR]

Ok, I haven't fried all my brain cells, it appears there were 2 different widths (track widths) a 58 1/2 & a 59 1/2 this is taken from a Hollander interchange manual.