I've been working on an old Thompson 252 I have a 5.7 one piece and the 14" flywheel scrapes the bell housing. If I space the bell housing back a 1/8 inch no problem the engine mounts line up perfectly where the original 898 did. I've tried the 898, Alpha 1 gen 1 and 2 housing and all do the same thing. Before anyone says is it the right flywheel have tried both marine and automotive same result. Any sugestions?

I don’t know why that is happening without being there. Obviously some of a parts issue.

Bellhousing to block dowels missing ? And/Or bolt holes oblonged ? Or offset dowels used by mistake ? Or…..

Can throw some things out there that may help. Your responsible if it does or not work for you. :wink

1) grind clearance on bellhousing where scraping. Term scraping to me means few thousands or or so material removed would remedy situation ?

2) They do make flywheel / flex plate spacers. I’ve never used one. Just throwing it out there.
https://www.google.com/search?q=sbc+...&client=safari

Never ran across such but would you be able to grind any out of the housing or would it be to much. Otherwise can you just shim it and call it good as long as everything else fits.

SB I’m a slow typer with my beat up fingers. 😂

Bell housing is a good fit so that doesn't make sense to me. I need to space it out about an 1/8" the thickness of 2 washers make work. I didn't know if maybe there is a bell housing spacer.

Here you go!

https://www.jegs.com/i/ICT-Billet/33...0-125/10002/-1

SB made me think since I needed to move the bellhousing farther I searched and found this Chevy Transmission Spacer Plate they make one 1/8"

SB made me think since I needed to move the bellhousing farther I searched and found this Chevy Transmission Spacer Plate they make one 1/8"

what drive is on the boat

Guessing it's Alpha-based if it started life as a 898 and using the same flywheel cover.

My thought is that it needs the 153-tooth (13 inch) flywheel vs the 168-tooth (14 inch). You will also need the appropriate starter to properly engage the flywheel (inline bolt pattern vs staggered).