F? S? What's it mean?

[RCpullerdude]

Just figure I'd put up this common topic.

What do the letters "S" and "F" mean?
"S" and "F" refer to the 8th character of your VIN. The letter refers to the engine. "S" is the light duty engine, normally equipped with EGR and a cat. converter. The RPO on the sticker in the glovebox for an "S" engine is L56. The L56/"S" is normally found in C/K1500's and 6 lug C/K2500's. "F" is the heavy duty 6.5. It has a slightly higher HP/TQ rating than an equal "S" engine. They do not normally have EGR, and have slightly different pre-combustion chambers. The RPO code for the "F" engine is L65. The L65/"F" is normally found in 8 lug C/K2500's and C/K3500's.

Anything else anyone else would like to add?

 

[AlbertaRedneck]

What about the P Van 6.5 RPO code? L57 IIRC

 

[RCpullerdude]

We should also have the C and J too, as this is a 6.2/6.5 forum. There really isn't any concrete info, but, IIRC, the "P"/L57 is N/A, for anything N/A, including vans, but I can't find confrimation one way or the other.

 

[Acesneights1]

An F engine can have a cat. My 2000 does. Also I know this is a new forum and some of us are migrating here from the "other place" but I think 6.2 should be a separate forum. If this site grows it will bproblem later on. JMO.

 

[AlbertaRedneck]

An F engine can have a cat. My 2000 does. Also I know this is a new forum and some of us are migrating here from the "other place" but I think 6.2 should be a separate forum. If this site grows it will bproblem later on. JMO.

Agreed

 

[RCpullerdude]

An F engine can have a cat. My 2000 does. Also I know this is a new forum and some of us are migrating here from the "other place" but I think 6.2 should be a separate forum. If this site grows it will bproblem later on. JMO.

I agree. Even though they are very similar, I really don't know too aweful much about the 6.2. Also, notice I never said L65's don't have cats? Actually, from what I've read, most L65's do have cats (soot traps).

 

[nvmtnlion]

Here are the biggest differences I can remember:

IDI Precup size. L-65 is optimized for power, L-56 is optimized for a balance of emissions/economy.

*Stock* ECM programming. HD has more power and a higher idle than LD

EGR.. HD has a more open intake with no EGR and no "Mystery Gasket" to go bad. IAT is cooler on HD.

I may edit this as more coffee dribbles into my brainz.

 

[durallymax]

Ggreat info guys. Glad we are starting to get some 6.5 guys over here.