Ben, you will have a lot of fun with gas scale, but you had better have a strong back. These suckers are big and can get heavy. As Tim noted, I have a T-6 gas scale made from Mike's kit. I have a Gizmo modded K-30 in my boat. Unless your cowl is wider than the T-6, you will not have room for a side exhaust. Marty took his rear exhaust down and thru the transom. Mine goes up and exits thru the turbine tube. If you go with a K-30 and the RMCK ball joint header, check for water leaks at maximum deflection. I do not have the best prop yet, and my speed is improving, engine has plenty of torque. You will need all the power you can get for performance. When you look at Mike's kit, remember that he scaled up his 1/8 scale kit. The frames and all parts are 20% further apart. You may want to consider some reinforcing. I used a combination of 1/16 and 3/32 sheeting. The 3/32 is 5 ply and the 1/16 is 3 ply. It's amazing the increase in strength without going to 1/8. I suggest you have your cowl before building the boat to insure it all fits together. All the Evansville boats last year were the 8255 hull except my T-6.Installations such as a side exhaust are different on the modern day turbine boats, so check it out.I'll be glad to share any info I have.
Harvey