I talked to my mechanic about converting my 6.2 to run biod.
An hour of work to change the injector return lines.
He says the main fuel feed/return lines do not need to be changed (contrary to posts on other biod sites).

He warned me that the injection pump will eventually fail due to rubber seals and a rebuild may cost $1k.

Will one of these rebuild 6.2 injector pumps address this?
http://cgi.ebay.com/ebaymotors/Chevrolet-GMC-6-2-6-2L-injection-injector-pump_W0QQcmdZViewItemQQcategoryZ33555QQitemZ804128 2813QQrdZ1QQsspagenameZWDVW

Or should I have them put a 6.5 pump on it?
http://cgi.ebay.com/ebaymotors/Chevrolet-GMC-6-5-6-5L-fuel-injection-injector-pump_W0QQcmdZViewItemQQcategoryZ33555QQitemZ803887 6916QQrdZ1QQsspagenameZWDVW

Or are his concerns unfounded?

So far this is the only mechanic in Portland that will work on my engine. Everyone else (even the GM DSU) don't want touch it and spread FUD about biod.

Merchants Auto & Truck Repair
(503) 232-7141
1810 SE 10th Ave
Portland, OR 97214

what kind of bio ar u talking about b-5 b-10 b50 or b-100 at the retailer .if it is the case no mod's are needed .if u are running SOV or WOV from artisanal production 2 tank setup with preheat system , the glycerine contained into those product can produce damage after many miles.20k now and no problemes yet with b-100 :) .

All damage cant be avoide if u get pure product or if u make it yourself(take time and effort and it's no fun:crazy: ).

Not SOV or WOV - probably B20 - B80 available from Sequential fuels.
I'm going to take a crack at making it myself soon, but currently we're brewing beer instead :0

I would keep the 6.2 pump,I don't see any advantages to changing it , various vendors on here have rebuilt pumps at less that $1000.

Pump rebuilds should run around $300. It has been said that with the new no-sulfur diesel, your pump will suffer the same fate as bio anyway, so whats the diff?

The pump should be fine... pour it in, and :grd:

Actually, using a B-20 your pump should last LONGER than with D-2, D-1 or kerosene blended and untreated Low Sulphur pump diesel.

Even Stanadyne released a Service Bulletin about Biodiesel blends and they actually recommended blending 10% for lubricity purposes. As far as cetane value (power) bio is as good or better than diesel depending on how its being made. Internal pump o-rings ARE NOT at risk of failure from biodiesel, however, if your pump has a lot of hours and the o-rings are saturated with diesel and brittle with age, then changing to a rich biodiesel blend (over B-20) could possibly cause a leak.

Best bet IMHO, have your pump overhauled by a reputable shop with a good warranty, cost should be 300-500 depending on what shape your pump is in and then just start using biodiesel at whatever ratio you desire.