Topic: 69 Mach One questions

[MarksMustang]

I have a 69 Mach One that has a 351C 4V engine. I know this motor is not original. I could care less about original. I also have a 70 Grande and also a 69 coupe. The 69 coupe has a 9 inch posi rear end with highway gears, an FMX transmission, and front disk brakes that I may put on my 69 Mach that has a C-4 transmission and an 8 inch posi rear end. Just wondering if the swap on these parts is worth the effort! What do you think?

[Joe AZ 2 PA]

I'd make the swap but I'm partial to fastbacks and Mach I's. . . . 

[Jeff73Mach1]

You will hate the highway gears with the Cleveland. 3.50 gears I ran were okay with the 4 speed, but when I went to my 5 speed they made 5th unreasonable at below about 85-90 miles an hour.

The Ford 8" rear end will hold up to any stock cleveland power levels and also up to mild increases if you maintain a close to original rear tire size and street tires.  Center sections can be found in many gear ratios and aren't too expensive.  Because of the lighter weight of all the internals, they even reduce the parisitic drive train loss compared to a 9" by a small amount  but . . .

Add slicks and that 8" won't survive for long.

I would recommend just finding a junkyard housing 9" the right width (should be under a hundred bucks) and buying a center section with rebuilt trak loc, and new gears bearings and seals.  I've bought 2 for under 600 a piece.  Buy some good axles (like strange) and you will have a rear end good for 6-700 ft lbs torque.  You can go with 35 spline axles for more money, but 31's are fine and I'm still running 28's (thank god for poor traction)

take off 8.8's with disc brakes are also finding there way into some old stangs

www.newtakeoff.com usually has a nice selection fairly cheap.

[Joe AZ 2 PA]

What ratio are highway gears? . . . First time I heard the term. . . . 

[MarksMustang]

I do not know the ratio. When the weather gets better, I will have to do more research on this and decide exactly what to do. The 69 coupe has a 351W with FMX transmission and the 9 inch rear end. I am looking forward to driving the Mach One this Spring, Summer / Fall ! I do not run it hard, but I like the power to be there when I want it! And I do not want to be afraid or hesitant to drive it anywhere I want to go!

[Joe AZ 2 PA]

Back in the days we used the term "Western" rearend for a car that was set up for the open road verse the strip. My 66 came with 3.00:1 on an 8". Mileage isn't bad but it sucks coming off the line. Planning to change it but not a high priority. They also had a 2.80:1 in an 8". Hope yours still has the tag on it. Saves a lot of time checking it by rotating the wheels. . . . 

[MarksMustang]

yeah, back in the day I pretty much just partied and drove.....only wrenched cars when I had to! Went to college for auto mechanics and learned to party more! What a waste of time! Now I am old, I am a Pastor, and I work on cars more than I really want to, but if you want to drive them, you got to wrench them, and there ain't nothin' like the classics! Yeah, back in the day....well I am not familiar with the term "Western" in that usage, but there is a LOT I missed back in the day! I am looking forward to driving this Mach One this year....before Uncle Sam regulates them all off the road....yeah...back in the day....sure is different now!

[Joe AZ 2 PA]

yeah, back in the day I pretty much just partied and drove.....only wrenched cars when I had to! Went to college for auto mechanics and learned to party more! What a waste of time! Now I am old, I am a Pastor, and I work on cars more than I really want to, but if you want to drive them, you got to wrench them, and there ain't nothin' like the classics! Yeah, back in the day....well I am not familiar with the term "Western" in that usage, but there is a LOT I missed back in the day! I am looking forward to driving this Mach One this year....before Uncle Sam regulates them all off the road....yeah...back in the day....sure is different now!

Old too soon, and smart too late. . . Not just you my friend. Pucker up the regulations are coming. They won't come thru the front door bacause of the attention and uproar they would create but they wiil sneak in thru the back door and any other way they can get us under their control. . . . 

[Mikey]

if its a Mach 1, it should have the 9" in it anyway....and is a direct bold in swap....