Here's the only solution that I can think of.
Go with the Dart 347, and give me your S-trim
seriously now,
Have you thought through how much work and money this would cost? Yeah it would be great to have a blown 347dart block, but that can't be cheap.
Are you happy with where it is now? Will it be worth the huge amount of cash for a mild improvement in horsepower?
Those are questions only you can answer for yourself.
As for me, and if money weren't an issue, I would definately go for it, and up the boost while I was at it
As for longevity, I haven't heard of any straight from the mouth experiences in which the 347 hasn't lasted. Yeah, we all hear the old wifes tales about them burning oil and not lasting, but you NEVER hear it from the people that it "happens to" just from a guy who knew a guy, whos cousin worked with a guy that had a friend with a 347 and it burned oil.
I LOVE my 347, and will never go back.
How bout you just let me borrow the s-trim, and i'll let you know how it works on a 347?
