348 bore max?

[Dean's 61 bubble]

does anyone have experience with a .125 bore(it still sonics .100) and i have been told, mostly by racers, that it should be at least .180 to .200 to be safe. Any thoughts, or experience....how about overheating problems from such a thin wall. Guess i could fill the water jackets with concrete, but... i really wanted to drive it on the street. Another possible problem is locating pistons---any help there? custom made from Ross? Thanks for any help, Dean

[W Head]

Dean, The 348 in my El Camino is .125 over and have had no problems. Have stock 348 radiator, but did install a smaller pulley on water pump and droped temp. about 10 deg. Have 160 deg themostat, but have 6 small holes drilled around themostat for a little more flow. Have 40 year old Jans 11 1/2 power slot pistons. Running re-worked 333 truck heads to lower compression. During Texas 100 deg. temp on hwy, runs around 195-200, would most likely would run cooler with new alum. radiator. Never had it sonic tested. It is a 1959 block I believe Ross makes .125 pistons.

W Head

59 El Camino 348-3,2s
59 Impala 409-2-4s

[bubbletop1961]

Check out aubreys site. He has .125 pistons listed on there.

[poison ivy]

348 truck block, .125 over bore, jahns cast buckets,mickey thompson alum rods,hard chrome crank, 11:5 comp ratio, racer brown roller, alive and well after 45 years , freshened last year, no over heat problem. poison ivy