clawless

I'm trying to use answers again and can hardly figure out what the question is from the ads and everything is flashing and changing? Are you kidding me? Now I remember why I left. Good bye ADHOO!

I have somewhat of a situation with a rebuilt motor I installed. Its an older merc 330 TR. Mark IV Chevy 454 with the thunderbolt IV ignition. Im usually pretty handy with a wrench and circumstances beyond my control lead me to have to do a long block swap myself. It went mostly well and I started it for cam break in yesterday, it didn't run very well at first but with a little distributor tweak is started and ran fine and I did the break in, 30 minutes-ish at ~2000 - 2500 RPM. Then I went to fine tune the timing and couldn't, after troubleshooting I realized I had the wrong rotor in there, it was the one for the 6 cylinder. It looks like it was only running on 4 or 6 cylinders during the initial break in.

How bad did i mess it up?

I have a boat with a TR drive and from the factory it has a 3 blade 19 3/4 x 19 alum prop. I'm coming up a little short on max rpm (about 2-3 hundred rpm) when empty, not to mention loaded and its a little sluggish out of the hole. I ran across a good deal on a PowerTech 4 blade stainless, it's a 18.5 x 19 cupped. I know you drop the pitch to add rpm but will over an inch of diameter drop help? Its a good deal but I don't want to buy a toad as this guy has had it sitting on the shelf for a while. I'm hoping for a better holeshot and good cruising speed - top end isn't a huge concern, just don't want to make it worse or effect efficiency drastically.

Thoughts?

So I'm rebuilding boat that has a belly tank and I have never worked with a plastic belly tank. After replacing the stringers, I'm putting the tank back in, the design has two braces across the top of the tank that keep it from moving fore and aft and up or down, however there is some lateral play in it now, about a half inch. So I know I need to take up the slack, however how tight should it be? Do I need to leave a little room for the tank to expand with the temperature? Or does cross-linked poly not expand and I should wedge it in tight? The factory install was a little loose however everything around the tank was completely rotted so I don't think that is a good gauge.

Thanks!