I ordered the stock 390. Carefully considered the T-bolt option, but couldn't make the cost and value compute. Stock engines are pretty smooth; the balancing aspect would have had the most value to me. Porting and polishing sounded really good, but this is a 2,700 RPM engine and it just seemed to me that the benefit would be much less than on a high-RPM race car engine. I really tried to find a way to quantify the benefit of doing it, but couldn't. Few are going to see the enhanced paint job. And there are a lot of other places to spend the extra 3,600 bucks. So I'll take my chances that the stock engine will be smooth enough. Ships mid-October. The T-bolt rep agree that dynamic prop balancing should be done with either engine, so I will do that. Prop is already here.
My engine is coming with one p-mag and a slick magneto. I will likely fly it that way before deciding to replace Slick with a second P-mag due to the high incremental cost of switching.
Last edited by Don E : 09-09-2017 at 10:18 AM.