Never heard of a 580 lift cam in any production 502 lV-Vll. If it's the 480/483 lift cam I'd think twice about it. So you mentioned dial indicating is a must. Any idea of hours on lifters. I realize it's a budget build but.... I can't remember if the gen V had lobe for mechanical fuel pump. I didn't think they did but possibly back on the gen Vl. Also not certain timing set/retainer plate come into play or not.

im not sure of the lift numbers those were just something i found on the internet. I opened the motor up last night. I think im gonna just have to bite the bullet and buy a cam. The 502 has the spring retainer plate in it like you said and the 454 does not have the bolt boss for it. I did run the block number its a mkv 454. Plus side is the heads off that 502. They are 088 heads that appear to be in good shape. Im gonna send them to get magged for cracks and run them. Since im buying a cam now anyway may as well just do the dome pistons and valve springs while im into it. I already have a rectangle port intake so that saves me a little. I guess a thousand bucks is still a good budget for a big block. Should make good power to. Anybody have any thoughts on a good cam for a .040 over 454 with 9.5-9.75:1 compression. 2.25intake valves / 1.88 exhaust

Are you going to change the impeller with the upgraded motor?

We ll see how it runs first

They guy i bought the boat off of years ago told me it was an AB impeller but ive never had a reason to take it apart so this may be it if the rpms are to high. I may try a differant inducer plate if its close but well see i guess. Thank you everyone for all the responses. Good to be in good company of knowledgable people.

Crane 168731. 226/236, 288/298, .587"/.610", 112*

Thanks ill check into that

Decent option and may find a good used one if you put in wanted section. Plenty of them around on shelves I’d imagine. Lots of choices just wouldn’t go any more lift and duration for your CI/build. jmo.

One piece rear main seal and a flat tappet cam would make it a gen 5 454. Only way to easily use a roller cam in a non roller block is to use aftermarket lifters with the tie bar.