as im about to re-build this b18c4 and 2 b20's i have laying around i thought it would be a good idea to finally invest in a dial test indicator.

mainly for measuring crank journals and crank end play. how accurate does the gauge have to be?

i can get one that reads accurate to 0.001 , or for more i can get one that reads to 0.0001

is anything in the engine requiring anything finer than the above measurements to check out of round/service limits etc etc?

 

Here's the way I look at it...

It's nice to know that the tool you're using is a little more accurate than it HAS to be. So in an engine where you're making measurements to 0.001", accuracy to 0.0001" seems like the best bet if you can afford it.

 

Agree. WIth any precision measuring tools the higher the accuracy rating the better the tool. Cheaper/ questionable accuracy tools have no place in engine building.