Hey there Oklahoma,
Hmmmm.. Lot's of good advice from everyone. We've got a 1950 F1 & we went the 351W/AOD/Mustang II IFS/8.8 inch rear end route. That's a loooong & very expensive road - I just wouldn't recommend it if you've got a nice driver at the moment.

It's much easier to pull your existing engine out & do all the oil gasket repairs & maybe some head work & then just put it right back in the same spot it came from. Replacing that flathead with a 302 is pretty intrusive - you will have to hack out the old motor mounts & weld in some new ones, get some new radiator brackets & install the new radiator, you'll probably put in a new starter, new electronic ignition, etc. Then you have to figure out how to attach it to the new transmission, pull that old trans mount out, etc. It's doable but it's long & ugly.

The Mustang II IFS is worse than doing an engine. Downtime - 4 to 6 months unless you are really good & dedicated.

Replacing the rear end with a a 9 inch or 8.8 inch is easy - do what you want back there - a weekend or two of work.

I've gone the other Modern Drivetrain route - I'd recommend you
take a shot at keeping your old flathead running & enjoy it. Once you pull these old trucks all the way apart it just seems to take years to get them back together again. (2.5 years for us with a lot of help & $'s). Good luck over there except when playing the Longhorns - just saying..

Ben in Austin

 

I took my wife for a ride in my truck tonight between storms...(we've gotten about 4 inches of rain, some hail, and tornadoes in the area)...the motor runs strong enough. It shows about 42 psi of steady oil pressure. After 20 mins it never got over 110 degrees. I really think the transmission is the biggest issue.

I think with the input I've received, I am about 100% positive I'm going to move forward with the T5 swap. While I have the truck down, I'll replace the seals and gaskets.

I used to giggle a bit when I heard the phrase "drive your truck for a while and she'll tell you what she wants," but not any longer. I heard it loud and clear tonight. Of all the opinions regarding what I should do, the flattie spoke the loudest.

Thanks Ben for the insight and experience. This isn't that hard a decision for me when I factor in downtime. I've had a 48 F1 project (read: basket case) for nearly two years that I haven't driven once because I started a big tear down before I ever got to enjoy driving it. I really don't want two pieces of garage furniture!

Now, hopefully the weather will cooperate and I can see a few Bonus Builts and some Effies in the morning at the SW Street Rod Nationals here in OKC.

Thanks to all, Kreg