I dont like chevy much becasue of thier leaky headgaskets and valve covers. Chevy is known for more hp than ford, per ci, but there is a -=-=-=-= load more that you can buy for the 5.0L then the 305/350. And u can squeeze more power out of a 5.0L. Ford is more reliable than bowtie in my opinion.
actually, there is about the same amount of parts available for the chevy 350 as their is for the ford 302...dont get me wrong, i am deffinately a ford guy, but i'd advise you to look in the summit racing magazine before making the assumption that their is more parts out there for the 302.
in fact, i think the chevy 350 may have even MORE parts available, and cheaper too. but the ford makes more power per cid, and is a lot easier to work w/ than the bowtie, simply b/c the electronics are simpler, and it has less clearance issues in a yj compared to the bowtie plant.