How much throttle?
 

How much throttle do I need to get on plane on a 88' 311 with 420's and trs drives and about how long should it take.

depends on a ton of factors, weight, tabs and drive position, etc. What style props are on the boat? If they are the original cleavers, it will take much longer to plane than with a set of bravos.

Either way, it's not going to jump up like a ski nautique!

Well there's 3 blade 25P mirages on there now. I usuall keep the drives all the way in and touching the water maybe 1 or 2 positions down. Weight is fuel of fuel and 2-4 adults w/ a cooler.

I just don't know if I need to mash the gas or baby it up. Would there be a better prop for my set up.

Regardless of prop you are always better off gradually adding in power until the boat starts to climb on plane and level out. Mashing the throttle adds alot of stress that will lead to premature wear and failure if done frequently.

My suggestion is find the RPM level where the boat climbs on plane and then throttle up gradually to that point and let the engine and drive train to the rest.

Every Formula I have ever owned responds the same way out of the hole..heavy gradual throttle until about 23~25 mph then back off until the nose falls over. After that it's a matter of how fast you want to go.

So far I've gradually eased into it just didn't know if mashing it made a difference. I think I get about half way on throttle and when the nose comes down then BAM she takes off.

Sounds like you've got it pretty much nailed.

If I start out with the tabs at about 6 and the drives all the way in, the boat will rise on plane about as quick with 1/4 throttle as it will with 1/2 throttle. There is virtually no bow rise. After it starts leveling out I bring the tabs to 2 and start trimming the drives out and the thing starts gaining speed like crazy. It takes longer to get on plane if I leave the tabs at 2 starting out and there is much more bow rise.