Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Hard to tell from pics without actually seeing, and feeling the cylinder walls, but that appears to be the results of piston slap. Can you feel anything in the shiny area, like scratches? OR is it more cosmetic? Then, I see the circular rings at the upper edge of the bore, right where the rings would ride at the top of piston travel(TDC)...that's not really "normal". I would have the block/cylinders checked before doing anything else...see if the cylinders are good enough to hone, or if they need to be bored to the next larger size. IF the cylinders measure out well, and are not egg-shaped, you can prolly get by with just a good hone job. I would also check the piston size, and make sure the pistons are the correct size of the cylinder bore size...they may be a smidge too large. If this is a 400 block, it may not be able to take a larger bore size safely.(but then again, I don't see any steam holes between the cylinders, so it's prolly not a 400..)
____________________________________ Joel Adams C3VR Lifetime Member #56 My Link
Vette(s): 1969 daytona conv. all original 350 350 380 4 sp w/air..and hard top
I am with Joel on this one also..do all the cylinders look like this one..or just the one pictured..I can see some hone in the shine area but the flash takes some of the picture away..maybe more pics with less or no flash but other than that can't do much with just one picture..oh are you sure its a 383..now is the time to get it right..you say the pistons are already 30 over..have a machine shop measure everything and see where and what would need replaced..you ask about rings..I have always been a fan of the gap less ones..gets the leak down close to 1%.
Vette(s): 1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.
IT would APPEAR to me that this engine does not have many miles on it. No carbon build up on top, and it LOOKS like a recent hone job has been done, with cross hatch lines. Also LOOKS like the rings were never seated correctly. Just my thoughts.
383's are usually 350 block and 400 crank, if you have to bore to 40 thousands and if not matching numbers I would go with a GM 383/425hp short block and bolt your other stuff back on or go with a long block, much quicker and comes with a 1 yr. or 24 k.
What is the piston number, it should be stamped into the top or maybe
cast into the under side. As said the lack of steam holes makes it more
likely to be a 350 block.
The 400 blocks are bulged in the outside walls from the large cylinder bores and some have 3 plugs per side.
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