yeh the 308 is looking to be a good option i dnt have the 253 or the 350 as yet they were just good options if i was to get the 308 with the trani and all that how much would i be looking at spendin??
Seriously dont even consider the 350 cause they are a real pain in the ass to get to fit right not to mention it will cost you between $1500-$2500 for k frame spacers, extractors, sump, mini starter (if you dont want power steer) or left to right starter conversion plus remote oil filters (if you want power steer) you would also need small bodied distributor like a msd to clear the firewall, spacers for the steering shaft. for the best fit you would be wanting to change to a vl k frame and steering rack as they leave more room for the extractors. then ad to that you'll NEED to run straight gas/lpg and remove the fuel tank and lines otherwise it would never get registered.
For simplicity i would go for a 308 backed by either a th350 or trimatic depending on if you get a turbo or tri pattern motor. all parts are off the shelf type and its an easy job really.
your wasting your time putting in a 253 cause the 308 has so much more potential for future mods and its the same fitment.