Re: VP 260A - What year?
if its factory red, its pre 1993. the casting numbers that you show are somewhat illegible. if its 3970010 its a 1969-1979 350.
http://www.thedirtforum.com/castings.htm
there should be a decal with the actual Volvo Penta serial number on it located on the starboard valve cover.
if its a AQ260a, it is a GM 350 260 hp which is the ubiquitously common generic 350 rating. there are two Gen I block changes that you should be aware of: the change to a one piece seal crank shaft in 1986 requiring the small crank flange, and the use of Vortec heads in 1996 requiring vortec specific intake.
if your replacing the whole thing from carb to flywheel, any SBC based Marine motor will work. if your replacing only the long block (block and heads) any pre 1996 will work if you use the right flywheel for the crank.