Teknick- Welcome to the 'Bolt!
You have exactly what I have, except with out the motor, but that may soon change. I have a t350 behind a 250-6 right now and am seriously considering changing to a 350 since I doubt my 283 will ever get rebuilt. The small block was an option in that year so the 350 will bolt in. Many have done it. The key thing seems to be the clearance at the firewall, it may be a bit tight for the dist.
On the tranny end of things you will have to take out the front crossmember, the one holding the 4 speed so you can get the auto in place. Best is to grind out the rivets so you can replace the crossmember later. Do the same with the one at the back that has the e-brake stuff on it. You will then have to weld on a mount for the tranny. E-mail me and I'll send you a pic of what I did. Everything then will fit back in place at that end. The output shaft on the trans will be fine splined, while the 4 speed should have more course splines. You'll have to swap that short little piece on the front of the driveshaft for one with the proper splines to fit. Not a biggy.
As for the rear-end. It depends. I have to double check my rear ratio, but I think it's 4-11 or so. With a 350, or any 8, you'll be a rocket off the line, but hiway milage, more than speed will be the downfall. If your truck previously had a 283 you may have better hiway gears. Someone here would know the ratio better. If it came with the 230 6 it's probably like mine and lower geared. I expect the 235's on the back of my truck won't last long if I go ahead with the 350 swap.
Getting traction in the wet can be a problem even now!
Good luck with the project.
BTW- '63 was the last year with the 'kneebuster' cab (wraparound windshield) and it has a unique grill, round headlight bezels. And Fleetsides are MUCH better looking than stepsides!!
