Help Identify SBC Chevy Engine block 327

[jmader]

Hey guys I need some insight into an engine block. Block casting number 3858174. Engine code F0505YM. Date stamp is E46. All my research says the YM suffix is only for a 327 used in 67 K10 to 25 and 68 C20 to 35. The 1966 date stamp is throwing me off a little bit. Is it possible the block was cast in May of 66 and then not used until the 67 production year? I'm hoping this will be right for my 1967 GMC K15 build. Any info would be greatly appreciated!

[Fitz]

Originally Posted by jmader

Hey guys I need some insight into an engine block. Block casting number 3858174. Engine code F0505YM. Date stamp is E46. All my research says the YM suffix is only for a 327 used in 67 K10 to 25 and 68 C20 to 35. The 1966 date stamp is throwing me off a little bit. Is it possible the block was cast in May of 66 and then not used until the 67 production year? I'm hoping this will be right for my 1967 GMC K15 build. Any info would be greatly appreciated!

F0505YM Engine code
F=assembled in Flint Mich. plant
05 in May
05 may 5
YM=327CI-V8 220HP, Man. Trans., 4BBL Carb., RPO=L-77

[bruceman1968]

Originally Posted by jmader

Is it possible the block was cast in May of 66 and then not used until the 67 production year?

Yes

[Fitz]

Originally Posted by bruceman1968

Yes

Not only was it possible but it happened quite often!

[jmader]

Ok thanks guys. The info I have says the casting # was only used from 1964-67 and the suffix YM was only used in K series trucks in 1967-68 so this has to be correct for my 1967 GMC K15 project right? Does anyone have any more information I might be missing? Is it possible I actually found the correct 327 for my build??!!

[bruceman1968]

Originally Posted by jmader

Ok thanks guys. The info I have says the casting # was only used from 1964-67 and the suffix YM was only used in K series trucks in 1967-68 so this has to be correct for my 1967 GMC K15 project right? Does anyone have any more information I might be missing? Is it possible I actually found the correct 327 for my build??!!

jmader, Your casting number, casting date, engine assembly code and suffix code, are all consistent with being built in the correct order, with the plausible dates for your truck. The YM suffix code is definitely correct for your 67, 4wd, 1/2 ton.

[Fitz]

Originally Posted by jmader

Ok thanks guys. The info I have says the casting # was only used from 1964-67 and the suffix YM was only used in K series trucks in 1967-68 so this has to be correct for my 1967 GMC K15 project right? Does anyone have any more information I might be missing? Is it possible I actually found the correct 327 for my build??!!

Hate to bust your bubble but the YM casting code was used on both C and K trucks. Here is the complete list which does not rule out this engine/trans combo for your K series truck but that combo was shared with the 2wd truck as well.

Engine Suffix Codes For C or K Trucks Only

SV= 250CI-6cyl with A.I.R.
SW=250CI-6cyl with A.I.R. &Automatic Transmission
SX=250CI-6cyl with A.I.R. ,H.D. Clutch, and 4spd Trans.
TA=250CI-6cyl with Manual Trans.
TC=250CI-6cyl Late 67's
TD=250CI-6cyl Late 67's
TE=250CI-6cyl with Powerglide or 3spd Automatic Trans.
TF=250CI-6cyl with H.D. Clutch & 4spd Manual Trans.

TS=292CI-6cyl with A.I.R. and 3spd Automatic Trans.
UH=292CI-6cyl
UQ=292CI-6cyl with 3-speed Automatic Trans.
UR=292CI-6cyl
UT=292CI-6cyl with Powerglide
VQ=292CI-6cyl with A.I.R.
VR=292CI-6cyl with A.I.R. and Powerglide
UN=292CI-6cyl Late67's

WM=283CI-V8 175HP, Powerglide, 2BBL Carb., RPO=L-32
WW=283CI-V8 175HP, Powerglide, A.I.R., 2BBL Carb, RPO=L-32
WA=283CI-V8 175HP, Manual Trans., 2BBL Carb, RPO=L-32
WB=283CI-V8 175HP, Man.Trans., 2BBL Carb., A.I.R., RPO=L-32
WC=283CI-V8 175HP, 3spd Auto. Trans., 2BBL Carb., RPO=L-32
WD=283CI-V8 175HP, Man. Trans., 2BBL Carb., RPO=L-32
WE=283CI-V8 175HP, Powerglide, 2BBL Carb., RPO=L-32
WF=283CI-V8 175HP, Man.Trans.,A.I.R., 2BBL Carb., RPO=L-32
WG=283CI-V8 175HP, Man. Trans., 2BBL Carb., RPO=L32
WH=283CI-V8 175HP, Powerglide, A.I.R., 2BBL Carb., RPO=L-32
WI=283CI-V8 175HP, Man. Trans., 2BBL Carb., RPO=L-32
WL=283CI-V8 175HP, Man.Trans., 2BBL Carb., RPO=L-32
WO=283CI-V8 175HP, Man.Trans.,2BBL Carb., RPO=L-32
WR=283CI-V8 175HP, 3spd Auto. Trans., A.I.R., 2BBL Carb., RPO=L-32

YC=327CI-V8 220HP, Man.Trans., A.I.R., 4BBL Carb., RPO=L-77
YD=327CI-V8 220HP, Powerglide, A.I.R., 4BBL Carb., RPO=L-77
YH=327CI-V8 220HP, 3spd Auto., 4BBL Carb., RPO=L-77
YJ=327CI-V8 220HP, 3spd Auto., A.I.R., 4BBL Carb., RPO=L-77
YM=327CI-V8 220HP, Man. Trans., 4BBL Carb., RPO=L-77
YR=327CI-V8 220HP, Powerglide, 4BBL Carb., RPO=L-77
YS=327CI-V8 220HP, Man. Trans., 4BBL Carb., RPO=L-77
YX=327CI-V8 220HP, Man. Trans., A.I.R., 4BBL Carb., RPO=L-77

[bruceman1968]

Dr. Fitz, that doesn't bust his bubble. All he's looking for is consistent with his truck. Doesn't matter how many other trucks it fits as long as his is one of them.

[Fitz]

Originally Posted by bruceman1968

Dr. Fritz, that doesn't bust his bubble. All he's looking for is consistent with his truck. Doesn't matter how many other trucks it fits as long as his is one of them.

Right you are!

[bruceman1968]

Originally Posted by Fitz

Right you are!

I just edited my post. I spelled your name wrong. Sorry about that. At least I got the Doctor right.

[Fitz]

Originally Posted by bruceman1968

Dr. Fritz, that doesn't bust his bubble. All he's looking for is consistent with his truck. Doesn't matter how many other trucks it fits as long as his is one of them.

That is true Bruceman! One thing, there is no "R" in the Gaelic prefix Fitz!