v6 to v8?

[still-floatin]

Got a 1995 stingray 609 which is 20'3". Got a perfect 4.3 which turns a laser 2 prop 5000rpm at approx 59ish on speedo. Need more and seeing that I drag race I got tons of sbc parts laying around. Anyone done the swap? I know the bellhousing is the same and assume the motor mounts are the same. I can get the thru hull exhaust fairly easy. Only looking to go 300-325hp. Dont want to grenade the alpha 1 with any more. Could I swap the alternator,pulleys,etc? Lots of questions but again this is my first inboard but wife is happy with the cuddy cabin.Thanks

[Darkside's Calling]

motor mounts are in a different position, if you don't mind redrilling the stringers that will work. Flywheel, bellhousing, and staret should interchange, id you match the crank flange type (1 piece vs 2 piece seal). If you have the parts I'd go for it, just remember to double misc parts budget and the time from what you initially plan....

Front engine mounts and components are teh same, just ues teh V-6 waterpump to match the belt rotation adn pulley position


If your starting with a later model roller cam clock adn vortec heads it's easy to make 350 hp, just watch your valve lift. Stock Vortec heads limit at like .480 valve lift. Need to machine the guides down a little for clearance....

[gregpro50]

59 aint bad for a V6 in that boat. I would say for the extra work needed just sell yours and buy a V8 boat.

[olmo40]

59 aint bad for a V6 in that boat. I would say for the extra work needed just sell yours and buy a V8 boat.


X2 , dragging an Alpha will grenade the top box asap .

[still-floatin]

I just bought the boat 3 weeks ago. I looked for 3 months before I bought this one. Everything is excellent but the engine. SBC are cheap when you have most of the parts already. Not looking to run 100 just mid 70's when needed.

[Euroski]

Should change the lower unit gear ratio as most V6's were about 1.65 to 1 V8's were 1.50 to 1. I was told years ago the alpha will live longer with 1.50's

[200VEGAS]

on gps, it sounds high, and you should borrow a gps so you have a real baseline anyways, imo

[still-floatin]

magellan gps315. 10 yrs old but still on. Stingray boats with zp hull are very efficient and quick for what they are. This is one reason i liked it. Stingray.com has tons of radar speeds on thier site also. Maybe i'll do a few upgrades to the 4.3 and see what happens.

[still-floatin]

sorry.stingrayboats.com or here is the link.They actually got 63.7 on radar with a vensura prop.
http://www.stingrayboats.com/products/reviews/tb03_06.html