Scalpel

iTrader: (4)

Thanks.

LS1derfull

A vernier or outside micrometer will suffice, btw GM uses 1/2 of actual diameter to come up with 19mm specs. etc.

Scalpel

iTrader: (4)

This is the one I have been using:
<img src="http://home.insightbb.com/~ominousvette/caliper.jpg" alt="" />

Is that good enough?

Scalpel

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong>A vernier or outside micrometer will suffice, btw GM uses 1/2 of actual diameter to come up with 19mm specs. etc.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I figured that. I calculated my basecircle to be 1.488" or 37.79 mm and when I compared it to a stock base circle you mention on a 2000 LS1 cam which was 19 I was like they must half it. Why do they do that?

LS1derfull

I would say its good enough, any decisions you make based on your measurements wont be affected by complete accuracy, say like pushrod length decisions.

RutanZ28

Use a good 1-2" micrometer!