we took my 1972 351w block to the machining guy and after few measurements, he gave me a list of items to get for him.
piston: +40
piston ring: +40
Main bearing : +10
Con rod bearing: +10
Based on this doctor prescription, i bought the following items from summit racing which came as a set:
SLP-E-251K40 PREMIUM PISTON RING SET Speed-Pro Hypereutectic Pistons H336CP4
SLP-1204M CAMSHAFT BEARING SET
SLP-224-41143
OIL PUMP
SLP-260-1028 GASKET KIT
SLP-3380CPA10 CONNECTING ROD BEARING PAIR
SLP-381-8015 BRASS EXPANSION PLUG KIT
SLP-5107M10 MAIN BEARING SET
SLP-55403B PRELUBE
SLP-H336CP40 CAST PISTON SET OF 8
SLP-SPG1 PLASTIGAGE
Final result and readings:
no problem observed in the working of the engine (visual and sound)
"compression readings improved from 9 to 12"
Question: i am reading in this forum that we should actually not have pushed for pistons bigger than +30 after engine machining / boring...am also reading in this forum that 1972 is relatively stronger block to be able to sustain +40.....am i really risking all the great work we have done so far by pushing for +40 (which means i should actually have changed the block instead of boring it....) what are the first symptoms i should be watching out if we have over-bored ? is there any preemptive measure i can take to avoid problems? i am not planning to race the car, it will be used for daily commute, yet i will not refrain from pressing the pedal ?