D2 valve guides

That isn't going to work. Valve stem diameters are larger on the D4 than the D2.

Found 3 of them http://www.machinerytrader.com/list/partssearch.aspx?PartNum=4F8359&btnPartSearch=Search&PST=Starts

That isn't going to work. Valve stem diameters are larger on the D4 than the D2.

I don't know my D2 valves measure 0.437 and the 315 (D4) guides are 0.4405 ID And both are supposed to be 0.814 OD and the lengths are D2 3.83 long and D4 4.25 long

OK, I stand to be corrected. I jumped a line to the D3400.
D311 Valve stem dia. new Int. = 0.435- 0.436", Exh.= 0.434 - 0.435"
Guide dia. = 0.440 - 0.441"
D315 Valve stem dia. new Int. = 0.435 - 0.436", Exh. - 0.434 - 0.435"
Guide dia. = 0.440 - 0.441"
You are correct on the guide lengths so yes, looks like you could cut down the D4 guides to fit the D2.

Where can you find specs like piston od and rebuild info the servicemans reference guide is very vague looks like I have way too much slop in pistons but it ran quite well before I tore it down Might need pistons but liners don't even have a ridge in them I would like to find a source for all measurements needed in rebuilding the d 311

Hi Scotty,
in my 43 years working at a Cat Dealer as a Mechanic it is stated by Cat that we do not use OD as a criteria in gauging a piston for wear limits.
They use piston ring to groove side clearance to rate re-usability.

Tests showed ring groove wear played a vital role and caused problems long before a sloppy piston did. As a rule unless dusted or seized a piston skirt does not wear excessively.

Cats latest Re-usability Guide for Pistons and Cylinder Liners that I have, SEBF 8001, still states this, hence, skirt to liner side clearances are never given. The Dealer Tech. Dept. would be able to show you one of these guides.
Cheers,
Eddie B.