Recently purchased a Corvette with engine out of a 1994 Camaro the owner listed it as a 383 LT1 thought LT1 was a 350 how can you tell the difference?

Answer 1

the lt1 is a 350 but if the engine has ever had any work done to it the guy probably have had .030 shaved off the cylinder walls and installed .030 larger pistons this gives you a 383 ABOVE STATEMENT IN INCORRECT A Chevy 350 is 4.000" bore with 3.48" stroke. Engine rebored .030" oversize is 355. A Chevy 383 is 4.030" with 3.75" stroke. To answer the original question, racing sanctioning bodies have a device that screws into a spark plug hole and measures displacement. Without that device, you cannot tell a 350 from a 383 without pulling off a head and measuring the distance the piston travels from top dead center to bottom dead center and the diameters of the cylinders. ABOVE STATEMENT IS GOOD BUT DOES NOT ANSWER QUESTION To get a 383 you use the crank out of a 400 small block or an after market crank. Because of limited space it can't be internaly balanced, so it uses the harmonic balancer specifically balanced for a 400 motor, which is not uniformaly round to balance the 400. You can tell a 400 balancer by watching the harmonic balancer when running at low idle to see if it looks like a chunk is missing from the back side of it. This is a sure sign of a 383 stroker.Some of the newer after market 383 cranks could be internaly balanced, then they would use a regular 350 balancer. I haven't seen one yet,but I build old school 400's and 383's. Check the balancer first.