My Baja 212 islander with 454 MPI would do between 65-67mph with a 3 blade 21 pitch bravo. That was with a BB so I don't think the small block will push it much past 55-60 unless it is built and has some torque.

Are you trimming up? Sorry but there was not reason to change gear ratio, and you were better off with 1.47. Where is the timing set? That 600 cfm carb should be fine out of the box so I hope they only adjusted idle mixture.

I will find out about timeing degrees where its at to day and yes tried triming I could be at 45 mph and hit the gas and it jumps 2 50mph np

And out of four ppl 2 tell me adjust timing while boats moveing and these r guys from a marien and 2 told me they adjust at 3000 rpms on land I so fed up

Set initial at 10 at idle, total should be in low 30s. That will be close.

You want total timing to be around 34*. That's a sweet spot for a SBC. Also, what are the numbers on your Thunderbolt module, should read V8-22 or such.

Call Zul

Anybody can build a low to mid 300hp 350 and make a 20ft performance boat run 60mph.

That's the cruel thing with this whole thread.

If you can use better english typing - i'm not that picky but you are giving me a migrain - maybe we can have a better conversation.

#1 - those gears are bullchit. They just took power away from you. Did you run the new motor build with the old gears ? And if so, what happened.

#2 - comp makes many different extreme marine cams. Please list exactly what cam they used.

#3 - what heads ? If factory, which style or year ?

#4 - which intake manifold

#5 - what pistons did they put in your new motor. Manufacturer and part# is needed. Not a description of flat top/dome/or etc as that can lie to you as far as compression.

=============================

Don't !

Many modules keep advancing past 3 grand. Some modules don't stop till 4200rpm. I think one goes to 4500rpm.