just recently purchased a 1965 p/u has a straight six now would like to upgrade to mild 350 and keep existing three speed tranny it it possible.
Its all up to the person who drives thier truck,I have a1966 c-10 shortbed fleetside 283 v-8 new motor bored 0.030 with a 350 turbo automatic transmission that fine no problems.700r are good trans. for the mileage 700r are the way to goLove automatics love the 2 speed powerglide,3 speeds are great and is 4 speed granny lows had 4 speed granny low here while back those trans. are heavy as SH%T. They weigh a ton.
I just switched out my six to a V8 in a 62. Yours being a 65......you are lucky. You should be able to use your 3 spd, flywheel and bellhousing from the 6. You will need to change one or both of the motor mount towers on your frame. Pretty easy swap as far as changes go. I used a low mileage motor that just needed valve seals and a rear main oil seal change. Plenty of power for a stock small-- small block.............the 4:11 rear gears help too
