Looking to see who is using what as far as sbc aftermarket exhaust goes and how you like it, gains in performance if any, After a few seasons on a stock 350/260HP in my 24 Pantera, i'm toying around with the idea of building a 427 sbc for it and she will need to breath. Wondering if true headers are needed like a set of Lightening headers or aftermarket manifolds will do the job like Imco Power Flow, Stainless Marine, or the new Hardin Marine Seaward Small Block Exhaust. Any input would be great!!!

The biggest sbc heads have 235 cc intake ports and 2.05 valves. Smallest big block has 235-2.06. And they call it a peanut port. This isn't a Camaro. That Dart block is more expensive then a good running complete 454. Then you'll find that is too small. Big small blocks are for hot rods. Big block...

You'll want Lightning/CMI headers for a big cube SBC. They will need to be dry or dry to transom. This is necessary to cam accordingly and not fight water reversion. The manifold choices you listed are all the same design. Short runner manifolds that dump into a riser. Not much scavenging effect vs the header design.

As mentioned though, if starting from scratch a BBC is a better option if it will fit.

A 235cc SBC 23* heads runner is much larger than a BBC's 235cc intake runner. (it's just the BBC's heads are longer)

The 23* SBC heads come in sizes larger than he 235cc heads. not that that matters hear.
Valve sizes from 2.08 - 2.100 are common now.

I agree in that this particular boat a BBC would prove to be better.

As a side note, a member on another site I am apart of built a mild 400+cid SBC with just Vortec heads and Eddie marine exhaust. Run 80mph in his 22ft BAJA with Bravo drive.

I already have a deal on a nice clean used Bravo drive from a friend. I was thinking of a mild 406 SBC as I can build it for quite a bit less than going the 427 SBC route. Maybe I should look more into that. I like the idea of staying with a SBC due to the less weight. I know a lot of 24 Pantera's have BBC in them but I love the way my boat rides as it is and am afraid going the BBC route with the added weight may change the way it rides too much. And yes I like to do things a bit different sometimes, LOL!

I'm not looking to go 85 mph. I want more than the 53 mph my stock 260 gives me. How about an honest 70 mph with a SBC?

427. starting with an aftermarket block. gonna be into it 6 to 10k by the time you have it in the boat. small block Pantera. Old like mine ? i think they stopped that setup pretty early. nice boat, but not what we would like it to be worth. if you part with it, scare up a used 330 or mag 454 and keep that engine. be fun in an 18 Donzi. what drive?

Boats a 1981 24 SE, originally had a 350/350 hp corvette engine in it, now has a stock quicksilver reman 350/260 which is how I purchased it. The tag on it says Its .040 over, so it's a 357 if i'm not mistaken. She runs great but it stinks when I'm the slowest out of everyone else I boat with.

if you want lightness and power what about an LS?

Alpha or pre-alpha drive?

I considered an LS swap... but it looks as it gets costly with the all new brackets and such and I could not find many who have done it.


Looks as if its a pre-alpha transom assembly with a first gen alpha drive. I'm guessing someone toasted the original pre-alpha drive. Lower has a nose cone on it.