[QUOTE=Gimmie1965;69267]Thanks JRMUNN,
Planning to make it a dually with 4 wheel power disc. My main concern is if the 305 will be able to pull it. I'm not concerned about speed. Looking at doing the 351m head,intake,exhaust swap in hopes that will help with pulling.
The 351M head, intake, exhaust swap won't do quite well with the 305, JR Munn was quite correct with that statement. This type of conversion will actually lower the compression ratio on the 305. You will be much better off like I mentioned before with a larger displacement V6 and a 401M that you think is too big is actually optimum for the amount of weight you intend to pull. Even if you come across a 351M that will be a significant improvement over the 305. As far as a dually conversion the 305 can handle that, for a while back in the 60's my father actually ran dual rear wheels on his 62 1/2 half ton with the 305D V6 and 3.54 gear ratio. Myself I yanked out the 305E out of my 68 K2500 and replaced it with a 478M V6 there is no substitute for cubic inches. The bigger V6 will still for the most retain the appearance of your 305.