The truck is 1974 F100 2WD, short bed, originally a 302 (currently 1971 351W), 3 speed manual column shift, 3.25 rear gear. I found this great write-up that answered a lot of my questions: M5R2 5-Speed Transmission Swap Into 67-72 F100 - FORDification.com

Since I’m starting from scratch, I initially assumed that I should go with the ZFS 542, but am now wondering if I should consider the M5R2. I have no experience with either, and am looking for opinions (yes, I know what they say about opinions☺). I am not looking to build a tow vehicle, but would like to be able to periodically tow something like a car trailer if needed. Is the M5R2 okay for limited towing? I drive the truck quite a bit, both in town and on highway trips. What are the pros and cons of each transmission regarding things like ease of conversion, cost, availability, drivability, etc. The rear gear is a 3.25, which I would like to keep.

A couple related questions:

In order to keep my speedometer cable, I believe I am limited to a transmission from 1987-1992 … is this correct for both ZFS and M5?

Cross member – I assume I need to use a cross member from an 87-95 truck with a 5 speed? … will that bolt-on to my 1974 truck without fabrication?

Hydraulic clutch – I think the Fordification link (above) explains this pretty well. Any other tips on this?

Driveshaft – Since mine is a short bed, I have a single drive shaft. What’s the easiest way to come up with the proper length drive shaft? Is there any chance that either the ZFS or M5 is similar in length to my current 3 speed?

Finally – Are things like my starter, clutch spline and pilot bearing compatible with the ZFS and M5?

As always, thanks for all your helpful answers and advice.

 

I posted my answers above. Hope this helps. Search for my name and M5R2 and you'll find some more tips.

 

Consider a Tremec TKO-500/600. Waaaaay easy.

Visit my '70's build thread linked in my signature.

 

Tndallas, thanks so much. I'm still reading through your related threads, but it looks like you've already done a lot of my homework. I thought there must have been other posts, but I must not have searched properly. And, its good to know that the driveshaft issue is fairly straight forward. Like you, I initially thought I should go with the ZFS, but it sounds like the M5 might be better for my light duty use. It sounds like you're happy with your M5 choice.

 

I did a lot of searching and reading and a lot of posts say the M5R2 is junk. But I think they wanted something for off road or pulling a trailer. The M5 comes out of a 90s truck so it has been engineered for this application. Light duty I think it is just fine. Other posts I've read said reverse is too high (too fast or not enough power) but I've not had any problems. Again, not towing but light duty.

I bought mine used off of craigslist for $2-300. I've replaced the shift forks twice. I might have gotten a bad/cheap set. When it is cold outside I have a little problem shifting until it warms up. But I didn't change my clutch so it could be partially due to that. But overall it is much better than the T18 and would be better than the 3 on the tree.

Don't discount HIO he knows his stuff.

 

Thanks HIO Silver. It looks like our replies crossed at the same time in cyberspace. Your post was not there when I replied to tndallas. I'm looking at your threads now. I'm familiar with Silversport and former Kiesler kits, but don't otherwise know much about TKO.

 

I went from an NP435 to a Tremec TKO-500. I got the trans n other bits from Modern Driveline.. they are really good guys. The only part I didn't have for my long bed was the front section of the two-piece driveshaft. It turns out a C6 is a touch longer than a Tremec and a correct 31-spline yoke so that's what I used.

Waaaay easy... and the stock mechanical clutch linkage works great.

 

I was asked in a private message to provide a couple of pics of my linkage.



Weld on original cross arm


larger view under dash of new linkage


I actually took it to a guy to have it welded. I think he used a muffler hanger.

The big think is to locate the clutch master just adjacent to the brake booster. I think mine is about 4 or 5 o'clock. There isn't much throw on the clutch master. You might want to measure this distance and then try to figure out how far down you want to make the lever. Since there isn't that much throw I wound up making a longer push rod for the clutch master. I got a bolt at the hardware store and heated it up and flattened it out and drilled a hole in it.

As you can see mine isn't exactly square but it gets the job done.

 

Thanks for the pics!

 

I have a 460 4x4 with a ZF5 in it and I love love love it. I have 4.10's, 38"s, and my RPM's are 2000 at 70mph. Perfect. When I finally decided to pull the trigger on the project I did a quick search on car-part and found one locally that only had 80,000 miles on it. $600. That being said, if I had the money, I would definitely go with a Tremec. I actually contacted Modern Driveline and spoke to one of the sales guys. He was super helpful and very friendly. He was NOT one of the guys you get sometimes who main mission in life is to get you off the phone. The only issue I had with them was price. If I could have afforded it, I would have bought it. Over $5k.

 

Thanks Dannen.