I found a 1978 Viking 220SI and later discovered that the Chevy 305 (225hp) had a spun rod bearing. After some diassembly it was clear I needed either a full rebuild or another engine. I found a 1974 OMC/Ford 302 on eBay and purchased it as it was already configured for a Stringer outdrive. Unfortunately the coupler on the Ford did not mate up with the outdrive. This may be because it was a 74 rather than a 78 as the Ford coupler part for a 74 appears to be different from a 77-78.

Did the Stringer drive change the drive shaft dimentions in 1977?
Can anyone confirm that the Engine coupler for a 1974 302 (170hp) is significantly different from the one on a 77 or 78 (175hp)?

The coupler I have for the 74 is a 982492 (now selling on eBay)
The one listed for 1977 and 78 is a 981948 which I am looking for, particularly if it will mate up with my 78 Stringer 800.

Any suggestions would be welcome... I got this boat 1 1/2 years ago and have not had it in the water yet!

Thanks