You will find lots of posts regarding this conversion on this site. It will require a V-8 bellhousing, flywheel, throttle linkage, exhaust system, radiator hoses, starter, etc. The rear mounts are the same, you can use the existing transmission and possibly the clutch depending on what flywheel you chose. Other wise there is nothing from the 235 that can be used on the V-8.
You will likely need a fan shroud as the V-8 is 5" shorter than the 6 cyl. If the current engine has a floor starter, you will
need a starter button or possibly another ignition switch.
There may be issues with the 2-3 shift linkage rods and the trans side cover if yours has the bellhousing pivot that was
used on 55-2 6 cyl trucks.
Fred

Last edited by rfs56trk; 12/31/2017 4:32 PM.

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine