i have a 70 mav and want to rebuild the rear. right now the gearing is 3.55. what i want to do is convert from a 4 lug axle to a 5 lug during the rebuild. id like to simply buy new axles with the 5 lugs. also the front hubs need to be 5 lug as well. i also want to regear. would a 3.05 gear be to low to hit 2000 rpms at 70 mph? this is my goal. i want to cruise and not kill the engine. 70mph is what i like to hold at on my commute. i will be swapping the 200 6cyl for a 302 once i get it built. the 302 will have roughly 300hp. im going to rebuild the stock c4 as well. is it possible to just order a new chunk and axles so i can just put it together myself and not have to pay a gear man to do it? please list specific parts if possible with links. i suppose ill stay with the stock axle housing as it seems fine.
Your cruising RPM will be dependent on the tires you are running but getting the 3.00 gear set will help a bunch. you could probably trade someone for their pumpkin and get where you want to be.
I've heard that the 4 lug rears have smaller axle bearings, so the 5 lug axles are not a direct fit. Without an overdrive trans you will need a 2.79 gear in order to run close to 2g @70mph.
You cant put 5 lug axles into a 4 lug housing....Axle tube/bearing dia. is smaller than a 5 lug. You are better off scrounging up a 5 lug axle and going from there...Yes with a 3 speed auto trans youre going to want to run 2.79s' or 3.00s' Tire diameter will also affect final ratio so keep that in mind. The C-4 from your 200 will need a 250/302 bell housing to allow you to bolt it to a 302. The V-8 trans also has a few more clutches/steels in it than the 200 trans soo...Keep that in mind as well...Good luck!
One other factor to account for in picking a gear is tire size. If you plan on a 302 build and change tire size it will affect the final rpm at any given speed. Also, if you do change an entire axle an 8.8 might be a good option simply because of parts availability.
thanks guys. so it seems my best bet is to just change axle housing completely for the 5 lug. can i order this all set up as i want? if so, any links to a good company. theres not many old cars left where im from so i doubt i can find an old rear. the only rear i have is off my old 70 F100 truck and im sure its to long. what other axles would fit if i can find them? but id seriously rather order new if possible. so as far as overdrive options go....i like the c4 but i would be willing to keep the 3.55 gear if i can get an overdrive trans thats as good as the c4 is. do they make these? sorry for all the simple crap questions, but i havent messed with anything old in about 10yrs so all of my past knowledge is lost.
Place a want add on the forum...That will net you a 5 lug 8" you can use. As for transmissions...The ford AOD Transmission is as simple a trans swap as you could hope for. Its as good as a C-4 with the advantage of an Overdrive gear which will let you keep the 3.55s' Frank (71 gold) makes a trans cross member for the AOD in a mav swap. No one currently makes a new/rebuilt 8" rear that you can buy and bolt in.
get a 5 lug rearend with stock gears 3.00 and put a 5 speed in and a 302 running lean will get you close to 30mpg at highway speeds and give you tons of power when you want it
ty sir! this sounds like what i want to do. the 3.55s are nice and would be killer if i had another gear, so ill do just this. since im not wanting to get the wrong one, can u point me to a link for the aod? is this an exact name for the trans or a generic covering a few versions?
AOD(Automatic Over Drive), was Ford's first O/D transmission used from early '80s till '93 in the full size models (those are actually 92.5), Mustang & 5.0/3.8 T-Birds/Cougar... I believe it was in 6cyl/5.0 pickups for a couple more years but those are longer so it's best to stick with a passenger car version(MK-VII Lincoln also used a longer version)... The ones from '88 have a improved lubrication system to tail shaft but I've never had a issue with a earlier one... What's paramount with a AOD is proper install and adjustment of the TV(Throttle Valve) cable, if it's disconnected or badly out of adjustment, the trans can slip and burn up the clutches in a very short time... I run one in my T-Bird with 3.73s, with the Trick Flow headed/cammed 5.0 has gotten 26 mpg at 65 MPH... Of course it's computer controlled, expect probably five MPG less with a carb...
Thats the one but... I dont like the "No speedometer drive gear" statement. Its on the output shaft of the trans and really needs to be there if you plan to run any type of normal speedo. I would call em and get clarification about that statement. The driven gear is the one that goes on the the end of the speedo cable...They are available from several sources...Seems like the going rate for cost as well...Shop around, you could probably do better price wise wilt less High performance stuff in it that you dont really need for a mostly stock street car.
It has to be there, AOD have drive gear teeth cut into output shaft... There are two versions with seven & eight teeth... Performance models like T-Bird Super Coupe used the 7T because of lower axle ratios..