You can find the 153 crank (3.25 stroke) in mid 60s through 1970 Novas. Those years may not be 100% correct but are close. You will probably have more luck finding the marine version though. The 3.25" (2.5L) crank was used from the 60s upthrough the 80s and maybe into the 90s in Mercruiser, Volvo Penta, and OMC marine engines. All these engines are the same and were manufactured by GM. Something to consider is using the 3.6" stroke (3.0L) crank. This would bring your engine up yo 3.0L since the engines these came in were also 4" bore. KRP sells the 3.0L crank rods and pistons for $500. I believe the pistons are Hyperutectic on the 3.0L also. I would think this assymbly would work in your block, but you will want to verify that it works with your deck height.
I wouldn't recommend going .60" over on any block especialy a 4 cyl. even though some Duke blocks can be safley bored .60" over. If you go .60 over you will need a new block when it is time to rebuild or if something scratches the cyl. wall. boring .60 over on a 4 cyl. is only going to give you a very small increase in displacement since it is only x4 cyl. A V8 is a different story since it is x8 cyl. If you are going all out on the Duke, use an S-10 block. They are cheap and I think the extra trouble is justified by the strength increase. It's what some racers use.
If you want to keep your block, TBI, and computer in the 88 your not going to be able to use any of the above cranks unless you find an adapter to put a sensor on the front of the crank for the DIS. Other wise, use the S-10 block and crank combo above with carbs and no computer.
Erik-
