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Gen 6 454 upgrades?


Well-known member
So my fancy engine fell through (sent money received nothing) so I found a gen VI Vortec 454 cheap and ran that. Obviously less power than my Caddy but, I built a new stand and cage for the BBC I was supposed to get so I just ran it. Upgraded to a 2.38 Ox drive to turn my 80" S 3 blade. It does OK but I'd like to get more out of it for the ground running. Boat will go over 50 on the water still but it's missing the low end. I converted it to carb with an old Wiend single plane intake (square port) and a 750 Holley double pump mechanical secondary carb. The carb change picked up a few hundred rpm over the junky 870 street avenger I had on the caddy and tried on the BBC. I have the prop on around 1.5 and getting 4500 rpm on the water. What would get me the most bang for my buck for an upgrade without costing a ton as I'm still trying to recoup my cash that was sent in good faith. I'm holding on to my caddy and all of the parts i have for it because I don't think I'd get what I have in the upgrades back out of it but it's just taking up space in my garage. I would sell it to buy some upgrades for the BBC possibly if I knew what it was actually worth.
I have and eventually plan a 496 build with it but for now due to circumstances I'm looking for advice on some easy (cheap) bolt on's for it. I'm wondering if the mismatch on the intake to heads could cause me some loss. (square port single plane on vortec small oval port heads) I'm just not sure there is much to gain with this thing due to the heads and pistons. I looked into a set of 781 iron heads but I assume I'd lose compression and thus power even with the better flowing heads without a piston change and I"m limited it seems on cam spec because the piston to valve clearance is not forgiving with these. I'm basically wondering if anyone has used one of these out of a truck and gained anything short of an actual build up.
I put an air gap intake on it and gained nothing over the single plane intake that was on it. I'm looking into a ZZ502 cam in it but getting confused about what other valve train parts I'd need to do the swap.