LOL, weird combination. Thoughts?
Iron 5.3 block bored to standard 5.7 size.
Stock 5.3 crank offset ground (more stroke) and reduced to Honda size rod journal.
Eagle H-beam 6.250 length Honda-journal rods.
Probe forged flat-top pistons (not custom, but a book p/n that works with the offset ground crank and long rods).
Factory 5.3 heads with the chambers welded up and recontoured to get the cc's hopefully in the upper 40's without a lot of deck milling, valves opened up to a 2.05/1.55 size, then ported runners for more flow.
Solid roller valvetrain, cam in the 250's/260's at .050, lift in the .600's.
Distributor conversion front cover, MSD billet distributor.
Victor Jr. intake (maybe Super Vic), tapered spacer, 850 carb on alcohol.
1 3/4 to 1 7/8 step headers.
That's pretty much the guts of it, should come out right at 355ci. I work at a machine shop so all the labor work is on the house. Really this is just kind of an R&D project, been wanting to do one of these for a while, if it does grenade all we'll really be out is some nice rods and pistons, the block, crank and heads are still production pieces. It will be going in my IMCA/USMTS style modified on dirt, car is only 2500lbs after race w/ me in it. We're looking for hopefully 550-575hp at the crank, about 500-ish ft-lb torque. Think we can get there with this little Frankenstein? Opinions are welcome.

