How to tell the year

[Hooptybass]

I just picked up a couple of 6.5 Mech Inj motors at a truck yard and i not sure how to find out what year they are , anyone give me a hand with that ?

Thanks Brian

[DmaxMaverick]

Look for the date code on the top/rear of the bell housing flange. Use our Dick Tracy decoder ring formula (located in a Tech Forum sticky) to determine the year of the casting.

[Hooptybass]

Ok heres the block casting on the rear pass side of the motor... just want to make sure im doing this right

K251 and a H100

[DaveBr]

If they really are mechanical injection 6.5's they could only be 92 or 93. The casting # on the back of the block last three digits should be 599

[Hooptybass]

the thing is they came outa bread trucks and they put 6.5 Mechs in them later than 92 and 93 .. im just tring to figure out what year they are

[DmaxMaverick]

November 25, 1991 and August 10, 1990, Respectively. The casting dates are somewhat vague compared to production dates (of the vehicles). Some upfitters stockpile chassis years ahead.

They should be "599" casts (last 3 digits of casting series), and could be either 6.2 or 6.5 bores (transition years). Because they were N/A, you'll have to measure the bore, even if they are labeled "6.5". For this reason, they may not be good candidates for more than a mild/moderate turbo upgrade. The internals (piston crowns, pre-cups) weren't intended for turbo use (more fuel/heat). They'll run forever N/A, and return awesome economy, comparatively speaking.

[Hooptybass]

Ok cool thanks ... Im using the one set of heads on my burb that had the cracked heads. Im hoping that they will be ok on a turbo motor ?