Is there room for it ? Then there is the mounts to change and glass in. Then there is the load of work to change the alpha one to bravo and all that involves with transom work etc etc. Then there is the huge weight difference between a 4.3 and a big block 7.4. I’d think it would be a little too much perhaps.
Simple answer is 'yes'... But you'll absolutely need to change the drive too, and that means a complete package change (engine, drive AND transom assembly).
) Just trying to drive that boat at 'normal' speeds will be problematic. The revs at 20 knots will be so low as to be outside the engine power band, and that means way less power where you really want it.... Yeah, it'll be a handful...
'Porkchop motor' ???????????
Even the 'least powerful' 383 is up around 320hp. With that power in that boat, he'll be looking at AT LEAST 60 knots, and that means a bit of 'air time'... Say goodbye to an alpha. And even with 1.47 gears, he's going to need a 23" or 25" prop. And 60 knots is the limit on an alpha before blow-out. All in all, this is getting silly.
Ok, ok. OP is probably already installing that big block to add drag. Seems he posted and disappeared anyway.
I really want a 6.2 mpi for my boat. Just can’t find one over here. Hens teeth unfortunately.
Build one. Take a standard 350 (5.7L) and put a stroker kit in it. Using the same heads and cam it'll take it from 260hp (non Vortex) to around 310hp. If you add Vortex heads and a nice cam, getting to 360hp is fairly easy.
Thought about it Chris...but the stubborn bit in me wants to stay mpi these days. no doubt the easy way is to do just as you say...many have told me likewise. but I just want to stick with mpi for the economy and smart craft function too. My own current mpi in the boat now is a great thing. She was fitted with a cam as a package when new, but as mentioned before, its just not well suited all round, with the ecu and fuelling just as original. lots of power up top, but almost lazy down low. So if I run a prop that will see her perform at her quickest at around 67 mph gps...that same prop will mean that she will hardly plane with much more than me onboard, not to mention the terrible struggle she has being happy at slower cruising speeds and just general all round use. So most often, I run less pitch that will see her happy cruising and planing, but will then of course hit the limiter at the top end all too easy...
Was going to say ^^^, especially the bits about economy and re-flashing.
Which means you aready have Vortec heads. With JUST the stroker kit, (and the cam you currently have) I think you'd be looking at around 360hp, and a metric s..t-ton more torque in the mid-range.
I haven't yet been aware of anyone here that can re map the ecu on these. If that was an option, I would 100% do this to the engine I have now. It over fuels at low rpm and likely under fuels near the top...or not as good as it could be. One good thing about the set up is the very guttural sound she makes at idle. Lovely noise from her. very different sounding from any other normal SB v8 I've heard. rough sounding lumpy primeval noise. Lovely.
Postage to USA to Whipple or any of the other ECU repairers/remappers is easy and cheap. Talk to them and see what's involved.
That's right Chris. Worth a thought then. Appreciate the advice.
I spent some time working near Cairnryan.. Truly beautiful. It was summer, and a bit cold for me, but a really nice area of the world.
If i recall he has a 5.0 mpi, 5.0 block i dont think can get bored out to 5.7 bore. NOt sure if heads are same as 5.7 suspect smaller 5.0 bore takes different valves but could be wrong …Which means you aready have Vortec heads. With JUST the stroker kit, (and the cam you currently have) I think you'd be looking at around 360hp, and a metric s..t-ton more torque in the mid-range.
Just do it!
Chris......
