This is a very common swap for a TF truck. Keep in mind that nothing from the 235 will fit a V-8. Also the V-8 engine is 5" shorter than the 6 so you will probably need a radiator shroud if you go with an auto trans. Also a new radiator with a trans cooler or a separate cooler. You can retain your stock trans by using a V-8 truck bellhousing. There are a number of overdrive options available also. Rams horns will work as they were factory to a V-8 powered 59. There are as many intake manifold/carburetor combinations as there are bellybuttons.
You may consider a new crate engine as opposed to buying an engine then having to rebuild it. The script covers will fit if they have the straight across bolt pattern, however they were not designed for crankcase ventilation. It was provided on the intake and rear of block on early engines.
Fred

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