Austin, been reading you posts and have enjoyed watching the progress. Some disagree wit your angle iron approach but I agree in your logic. When installing heavy manufacturing equipment, the pads are always grouted, not for bonding but for a solid base which also spreads the load. CorrectCraft also used steel frames under their engines as was mentioned. I like the approach and may do the same on my future project. Regarding the exhaust outlets, the model you referenced looks nice and clean, it would update the look of the boat as well. If you want a more traditional look, I found some used ones for both my boats on the CorrectCraft group, someone is always parting out something. Keep up the great work!
