I think this question has been covered a time or two, but thought I'd ask again just in case anyone has new info. I've got a '72 Mav that was originally a 6cyl car that I've now swapped in a built 302 and T-5. Still has the original rear end with 2.73 gears, which is great for one wheel tire roasting and unlimited top end, but is really no fun for anything else. I would like to change to 3.80 gears, posi, and 5 lug axles so I can put some of those super cool Torq Thrust II's on it. The question is: Is there any way to swap in 5 lug axles? Are the axle bearings really a different size, or if so, could you use 4 lug bearings on a 5 lug axle to make it work? I really don't want to swap the entire rear end out if I can help it, especially since Mav 8 inches seem to be hard to find. Thanks, and sorry to re-hash an old question! Jason
You may have to swap the backing plates while you are at it - I think 4 lugs are 9 inch drums and 5 lugs are 10 inch drums ...
Thanks for the info! I had thought I'd read somewhere that the 4 lug axles (in an 8 inch rear end) use a smaller bearing. Guess that's not the case. Anyway, I'll give it a try and find out for sure! Also, great point on the backing plate! Hadn't thought of that one.
It is the case apparently. I think Craig has tried it. The 4-lug bearings are supposedly smaller than the 5-lug axle bearings.
I just converted my car from 4-lug to 5-lug. I pulled the entire rear out of my parts car - took it apart, cleaned it up, painted and detailed it and put it all back together with new brake shoes, cylinders and pads. More hassle than just swapping the axles and plates but no worries about anything working properly and now looks pretty! Dan
Axles Check the local parts store, they list the same bearings for 72 thru 77 here at the AZ. I think the 70-72 with the 7 1/4 rear are different and also the MII 8in. Double check numbers with NAPA or another parts outlet, AZ's are known to have errors in their pc's. Numbers are only as good as the guy entering them. Got a set of bearings for a 302, wrong oversize, back to the store. The next set was for a Chevy, got the mgr. and he finally came up with the correct ones. Have a small town parts store some 45mi from here, visit regularly to bench race over coffee and such. The owner can go in the back and pull parts without looking up numbers and such. Last of the old days that I remember. With so many different cars now and new fangled equipt. is a real chore to sort through the maze of applications on the computer. I just realized that I'm sounding just like the old timers who said that Henry's model T would never replace the horse!! Oh well, us old guys get that way sometimes.
Great info guys! I hope to make a trip to my favorite junk yard in the next few weeks and drag a complete 5 lug rear home. That way we can measure up everything and find out for sure! Thanks again for all the input!! Jason
Re: Axles All late 1972-1977 had 5 lug 8" rears so yeah, they are going to have the same part #. Some 1971-2 6 cyl cars had 8" 4 lug rears, and that's the rear we need to be looking at.
