I had the identical situation without the buggered water pump hole.
What i did is exactly what you should not do, but for a budget build this engine is a monster.
Total engine noob but I wanted to do this on my own and with what little money was invested the risk was low
Block was standard bore, with a ridge. Bought (borrowed but never returned) a ridge tool from local store (do NOT use the Lisle tool, its junk, use the OTC if available)
Measured the bores and they were nice and straight and within tolerance. No one believes that part given it had a ridge, but it was/is
Used a ball hone, the flex hone I think it was 4.5" which was needed for the 4.32 standard bore
Local guy had a set of dome sealed power standard pistons with moly rings for sale for $250 USD (just over $325 CAD) because he decided to do his block the right way, these had been sitting on his shelf for a decade hence the price as he was just making room
Put the engine together, I used 75cc eddie heads, so not sure what my final compression is but has to be at least 10.50 the last time I did the math
Runs clean, has great compression and on the higher end of still very good on a leak down which I expected. No piston slap when cold. I used standard bearings on the home polished crank, so i am running 10w40 oil and oil pressure is quite good, 60 cold and 30 hot idle which is pretty good given I have on the higher side of clearances in the rods, mains were still pretty good. I have the plasti gage numbers written down somewhere
Anyway, the thing is an absolute beast, does not burn oil at all that I can see or smell. Idles perfect, stays cool, and melts tires for days.
is this the right way, no way. Will it last, for how often i drive the car yes it will.
Not telling you to do what I did, but I started my car building very late in life, and wanted to build my own engine instead of writing checks to everyone including summit and machine shops and I really lucked out.
