I'm building a ' 48 Ford F1 truck. The motor I'm dropping in will be a Ford 390FE, in the rear I've got a Jag IND suspension and diff. What will be the most suited four speed transmission for this set-up? (I will use the truck as a cruiser).

 

there's no readily-available overdrive option available...i think the easiest 4-speed would be a toploader. it came behind the FE from the factory, so its up to the abuse of a 390.

 

I just had a look at the top loaders. What do you think will be the best for fuel consumption and cruising manual or auto?

 

MT will be better for MPG. Auto for "cruising".

What axle ratio and tire are you going to run?

 

Axle ratio is 3.31:1 and I'm planning to go 18 or 20" at the back

 

18" or 20" wheels, ok, but what tire size and what is the diameter of that tire?

 

I was thinking 325/25x20 so that will be about a diameter of 26".

 

don't count on "good" mpg with the fe , they suck gas .
i got mild 390 and c6 cruises good , step on the skinny pedal and i can watch the gas needle move (but so does truck !)

 

1:1
3.31 axle
26" tire
=
23 mph per 1000 rpm.

60 mph will equal 2567 rpm, plus TC slip if you go C6.

Fine for short trips, but a little low for a cross country jaunt methinks.

So, C6 or toploader works. You could find a 4 speed OD patterned on the toploader, and have 3 speed gearing 1-2-3 and 4th over.

Toploader Imposters

Kee even sells a topshift set up for the performance trans. Not cheap...

 

the toploader with od is not very strong
ive ruined more then my share of them with my driving habbits

anyway
i had found this website that was very awesome

Ford FE Transmission Adapters

if you have the money it will let you use nearly any od trans you want
personally id get a 200r4 or a 700r4 trans built up and use that because its all mechanical. the aod is a waste of money (blown many of those up behind a sbf) even when built, so unless you want to go electronic and sink a bunch more money into it, the "r4" trans is the wy to go

 

What about the T85N 3spd+OD that came behind the trucks from the factory? I didn't even know about these until recently but it seems there are a few people who still use them. Reportedly plenty stout. Maybe it's just that these are hard to find? There's one in the classifieds of the other FE forum for $150 needs rebuilt.

 

I'm drawing a blank. What truck did that come in.

 

1965-1973? maybe 76? F series trucks. The other models of T85, the T85C I believe, came behind the cars in the 60s.

 

I never knew those trucks had an OD variation of that trans. I was thinking early 80s trucks.
To the OP original question, there are a lot of nicer shifting manual trans to be using in front of a jag rearend. If the money is available to do a tko500 then that's the way to go. But if an auto is wanted, you gotta use an adaptor like I linked.

 

The T85 set up is a 3 speed on the tree with an electrically shifted OD bolted on the tail.