Nice project boat. You are a lucky guy.
A 29 H&H Center console would be a "roll of the dice" as far as resale.
From your post I get the sense that your are considering a center console setup because of placement/fitting the 6CTA your have into the boat. The 6CTA is a mighty BIG engine for a 29 H&H, weighs close to 2000 lbs with gear.
BTW, that is a very nice engine and with 450 ponies and all the tourque plan on spinning a max wheel on the boat of 28" diameter.
Here's a thought and one I would seriously consider if I was lucky enough to have the boat and the engine to work with.
How about placing the Cummins "back a bit" with a ZF vee drive?
2:1 gear, maybe a little less, the boat would scream.
You'd have a nice height engine box back away from the helm station and you'd move the weight of that 6C beast closer to the center of the boat where it belongs, gain cabin space and you'd be able to keep the helm top you have.
I was considering repowering an old 25 BHM lobster boat with a 6BTA 220 vee drive. Deal fell through but would have been a very nice setup.
For what it's worth,
Bill D
