Hi everybody. I have a low-mile 2.5 TBI block that I'm planning to "build" for my turbo Spirit. Before taking it to the machine shop, I wanted to learn how to measure stuff myself with my new micrometer and bore gauge. If anyone could "check my work", I'd really appreciate it. Measuring thousandths-of-an-inch in new to me haha.

First, did I measure out 3.445 on the micrometer correctly?


And second, where can I find the tolerances for our engines?


As I checked taper and out-of-round, everything was within .001 tolerance (most of the measurements were within .0005 except one). Hopefully I'm interpreting this correctly.

Am I correct in saying that this engine is within spec? Also, what kind of tolerances are y'all running with forged pistons?


Thanks