Zf-5 gas vs diesel bolt patterns

Reply Subscribe

Thread Tools

Search this Thread

Apr 9, 2018 | 10:30 PM

78Broncoinpieces

Thread Starter

Mountain Pass

Joined: May 2006

Posts: 217

Likes: 5

Zf-5 gas vs diesel bolt patterns

plan is to put a ZF-5 in my 78 Bronco, 460 engine with NP203, currently 3.50:1 gears.
truck will be 95% street use so the 1st gear of the wide ratio/gas version, 5.72:1, will be way too low.
I'm thinking the close ratio diesel would be a better fit, only 4.14:1 first gear on that one.
I've been told the bell housing pattern is different, some but not all of the bolts will line up.
can the diesel bell be easily modified to fit a 460? locator dowels OK? any starter fitment issues?

Thanks

Apr 10, 2018 | 05:06 PM

85e150

Super Moderator

Joined: Apr 2004

Posts: 34,466

Likes: 2,798

Everything I find says two bolt holes need to be redrilled, and a pin relocated. No comments about starter.

It's been done.

Apr 14, 2026 | 07:25 PM

freddy’s f150

1st Gear

Joined: Apr 2026

Posts: 1

Likes: 0

Quote:

Originally Posted by 78Broncoinpieces

Did this swap end up working for you? I am sitting in the same boat right now of trying to figure out if it’s even worth it or to just stick with my c6

Apr 15, 2026 | 03:24 PM

FORDF250HDXLT

Fleet Owner

Joined: Jul 2006

Posts: 20,322

Likes: 789

From: Mi'kma'ki

Quote:

Originally Posted by freddy’s f150

Did this swap end up working for you? I am sitting in the same boat right now of trying to figure out if it’s even worth it or to just stick with my c6

It's by far best to try and find a Ford bellhousing pattern than try and use Internationals of course. These trans shouldn't be that hard to find.
As for if it's worth swapping to an OD trans at all (Ford to International pattern aside) that really depends on how often you use your truck and what speeds you drive at.
If you only put on 10k miles or less per year and drive mostly 45mph on back country roads, it's not going to be as worth it (perhaps not at all) of course compared to if you drive 20k miles per year and run 75mph interstate speeds most of the time.
If you're right in the middle, putting on 15k per year, driving average speeds of 55 to 60, I'd say it's worth it, so long as you plan to keep the truck a few years.
If you're driving a lot of those miles empty, not doing truck things, then no. Wont be worth it. Keep truck as is and drive a small 4 cyl car when you don't need the truck to get 30mpg+ and blow the small OD benefit out of the water (save thousands vs hundreds. Big oil will hate you, but your wallet with love you.)

Last edited by FORDF250HDXLT; Apr 15, 2026 at 03:32 PM.