1970 I-6 250 cu in into 1954 pickup?

[mr48chev]

I've had both a 194 and 250 in my 48 at different times.

You need a cast iron V8 bellhousing from a late 50's early 60's Chevy truck. That lets you bolt the 250 to the bellhousing and you can use the factory 54 mounts under the bellhousing.

You will have to fabricate your front mounts and mine are the worlds ugliest motor mounts so I am not showing any photos of them.

On mine I shortened the shaft on the waterpump and used a shorter pulley off a V8 for clearance between the pump and radiator and there still isn't much clearance.
I drove mine for over 15 years with the 250 in it until I wore it out so bad it was using more oil than gas. That engine probably has 250K on it (95K when i put it
in) and has never had the head or pan off.