What motor?

[jdub]

I know I have a ton of questions but you guys are helping me with all sorts of things! I need to know the timing for my chev 350 so that I can adjust it. Problem is... I dont know the year of my motor, nor do I know what it came out of. It's in a 83 cj7. Some have said it looks like a pre 80's block, fact is that just doesn't help. Is there a definate way I can identify it? Codes located somewhere? I don't know where to begin to look. I began to look around the front and sides of the block, but didn't find anything.

Any help would be appreciated!

jw

 

[bobmed]

look on the drivers side behind the head.
there should be a casting number there on a ledge.
the last three digits are on the side of some below the head.
if the number on the ledge is the size in liters (5.7) it would
be a later block.
a web search for casting numbers will find the year the block was made.
I found that I have a 1987 350 with 1980 305HO heads.
I'm not sure on the timing as this is the first Chevy engine
I've had
I have a book that lists some of the numbers so if you find it let me know and I'll see what I can find.

 

[DaveB]

I have usually set my 350s to 10-12 degrees advanced. Start there and set it back if it pings.

 

[jdub]

I found a 3-digit number on the bottom side of the "v" wall it had stamped 379 or 397 I forget which and its not with me right now. Is that it or is the number usually longer?

Thanks Dave that gets me in the right direction.

j

 

[78mitsu]

83+ blocks will have a one piece rear main. there will be a aluminum housing that holds the seal on the back of the motor. easiest way to tell if it's a after 80s block, the block is the same until the gen 3 blocks.
Here is the list.


GM casting numbers are usually cast into the side of the block under the exhaust manifold, and sometimes on a tab next to the head on the back of the engine.

Hope this helps.

CASTING#.....SIZE...YEAR...MAIN CAP BOLTS....NOTES

140029.....350...80-84...2
330817.....400...72-80...2
355909.....262.....75....2
355909.....305...76-79...2
360851.....262...75-76...2...Monza V-8
361979.....305...77-79...2 or 4, some Canadian assembled heavy duty blocks have 4-bolt main caps
366245.....350...78-79...4...Bowtie
366286...................4...Bowtie, siamesed,
straight nodular iron main
caps, 2-piece seal, 4.00-4.150"
bores, 2.45" main journals
366298...................4...Bowtie, Aluminum, billet main caps, 3.398" bore with sleeves, two piece rear main seal.
366299...................4...Bowtie, Aluminum, nodular
iron splayed caps, wet sump,
4.00" bore
389257.....302.....67....2
393288.....283...65-67...2
460703.....350.....78....4
460776.....305...78-79...2
460777.....305...78-79...2
460778.....305...78-79...2 or 4, some Canadian assembled heavy duty truck blocks have 4-bolt main caps
471511.....267...79-82...2
3556519....283...58-61...2
3703524....265.....55....2...No oil filter
3720991....265...56-57...2
3731548....265...57......2...No side motor mounts
3731548....283...57......2...No side motor mounts
3737739....283...58-64...2
3756519....283...58-62...2
3782870....327...62-67...2
3789817....283...62-64...2
3789817....327...62-67...2
3789935....283...61-64...2
3790721....283...62-64...2...Chevy II recessed oil filter boss
3790721....327...65-66...2...Chevy II recessed oil filter boss
3791362....327...62-67...2...Chevy II recessed oil filter boss
3792563....327.....65....2
3792582....283...64-65...2
3794226....283...58-63...2
3794460....327...62-64...2
3830944....327.....63....2
3834810....283...64-66...2
3834812....283...62-63...2
3837739....283...58-62...2
3849852....283...57-66...2
3849935....283...65-67...2
3858174....327...64-67...2
3858180....327...64-67...2
3858618....350...68-76...2
3862194....283...65-67...2...Chevy II recessed oil filter boss
3862812....283...62-64...2
3892657....302.....67....2...Z-28 Camaro
3892657....327.....67....2
3892657....350.....67....2...Camaro
3896944....283...66-67...2
3896948....283...66-67...2
3903352....327.....67....2
3914636....307.....68....2
3914638....307.....68....2
3914653....307...68-73...2
3914660....327.....68....2
3914678....302.....68....2...Z-28 Camaro
3914678....327.....68....2
3914678....350.....68....2
3931174....307.....68....2...Truck
3932371....307...69-73...2
3932373....307...68-73...2
3932386....302.....69....4...Z-28 Camaro
3932386....327.....69....2
3932386....350.....69....4
3932388....327.....69....2
3932388....350.....69....2 or 4
3933180....327...68-69...2
3951509....400...70-71...4
3951509....400...74-80...2
3951511....400...70-73...4...Some replacement blocks had 2-bolt main caps
3956618....302.....69....4...Z-28 Camaro
3956618....327...68-69...2
3956618....350.....69....2 or 4
3956632....307.....69....2
3959512....327...62-67...2...Was also used for some "CE" replacement blocks
3959532....283...64......2...Used for some "CE" replacement blocks
3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4
3970014....350...70-76...2 or 4
3970020....307...69-73...2
3970024....307...69-73...2
4715111....305.....80....2
6259425....350...69-76...2
10036033...350...........4...Goodwrench crate motor, 2-piece rear
seal, "Hecho en Mexico"
10046164...305.....86....2
10049804.................4...Aluminum, Pontiac Super Duty version of Gen.I SBC, 4.00" bore, 350 mains, 2-piece rear seal, splayed caps, GTP race block
10051182.................2 or 4...Bowtie, 3.75"-4.30" bores, 1 or 2-piece rear seal
10051184.................4...Bowtie, 4.00"-4.155" bores, 1 or 2-piece rear seal
10054727...350...86-up...2 or 4...one piece rear seal, some "Made in Canada"
10066036...350...........2 or 4...Target Master/Goodwrench crate motor, 2-piece rear
seal, "Hecho en Mexico"
10066038...350.....92....4...Goodwrench crate motor, 2-piece rear
seal, "Hecho en Mexico"
10090511...350.....90....2...LT-5, ZR1 Vette, 375hp
10125327...350...92-up...2 or 4...Gen.II LT-1, reverse flow cooling
10125327...350...96-up...2 or 4...Gen.II LT-4, reverse flow cooling
10134398.................4...Bowtie, Aluminum, 4.125" bore, 2.65" main journals
10134996.................4...Bowtie, Aluminum, 4.125" bore
2.65" main journals
10153558...350...91-92...4...LT-5, ZR1 Vette, 375hp
10168588...265...94-96...2...L99, Gen.II, 4.3 Liter V-8, Caprice, reverse flow cooling
10199001...350...93-95...4...LT-5, ZR1 Vette, 405hp
10243878...305...96-98...2...Vortec truck, roller cam, one-piece rear seal
10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal
12550592...350...97-up...crossbolted block, Gen.III, "LS1", aluminum
12551358.........99-up...Gen.III, 4.8L or 5.3L, cast iron, truck
12551364...364...98-04...crossbolted cast iron Gen. III, 6.0L, truck
12559378...350...99-up...crossbolted block, Gen.III, "LS1", aluminum
12559846...350...98-up...crossbolted block, Gen.III, "LS1", aluminum
12560621...350...98-up...crossbolted block, Gen.III, "LS1", aluminum
12560626...350...99-up...crossbolted block, Gen.III, "LS1", aluminum
12560629...350...99......crossbolted block, Gen.III, "LS1", aluminum
12561168...350...01-up...crossbolted block, Gen.III, "LS1", aluminum
12562174...350...98-up...crossbolted block, Gen.III, "LS1", aluminum
12568952...364...05-up...crossbolted block, Gen.III, 6.0L, aluminum, LS2
12566910...325...04-up...crossbolted block, Gen.III, 5.3L, aluminum, truck
12571048...325...04-up...crossbolted block, Gen.III, 5.3L
12573581...364...98-04...crossbolted cast iron, Gen.III, 6.0L, truck
12577184...364...98-04...crossbolted cast iron, Gen.III, 6.0L, truck
12577396.........02-up...Gen.III, 4.8L or 5.3L, cast iron, truck
14010201...305...80-85...2
14010202...305...80-85...2
14010203...305...80-85...2
14010207...350...80-85...2 or 4
14010209...350...80-85...2 or 4
14010280...267...79-82...2
14011064...350...83......4
14011148...350...87-89.......Roller cam, one-piece rear seal
14016376...267...79-82...2
14016379...350...77-79...2 or 4
14016381...305...80-84...2
14016382...305...79-84...2
14016383...305...80-85...2...Truck
14079287...350...86-90.......Truck
14088526...350...87-89.......Roller cam, one-piece rear seal
14088548...350...86-88...2 or 4
14088551...305...86-87...2...one-piece rear main seal
14093627...305...87-91...2...Roller or flat tappet cam, one-piece rear seal
14093638...350...87-95...2 or 4...Roller or flat tappet cam, one-piece rear seal
14094766...305...86-up...2...One-piece rear seal
14101147...305...85-up...2
14101148...350...86-90...4...One-piece rear seal
14102058...305...87-91...2...Roller cam, one-piece rear seal
22551656.................4...Rocket block, 4.00"-4.190" bores, 2.45" main
journal sizes, splayed caps, dry sump,
2-piece rear seal, 9.025" deck

 

[78mitsu]

for a stock GM the timing should be 7 + 1* for every 1000' above sea level. so at 5000' 12*

 

[mbryson]

83+ blocks will have a one piece rear main. ......

I'm 99.999999999% sure that's '86 and newer with the one piece rear main. (2nd year TPI motors (Firechickens, Camaros and Corvettes) for sure---at least that's how the General spec'd it........you might still have some older motors in trucks or ??? where people wouldn't notice)

 

[jdub]

just from your help I know it's a 70-76' and the timing is to be set at 10-15, and to be exact 12 is where i'll put it!

thanks guys!

Thanks RME
I used to drive around to parts stores and 4x4 shops to figure things out. I owe you guys for the gas, even more for the correct info.

john

 

[78mitsu]

I'm 99.999999999% sure that's '86 and newer with the one piece rear main. (2nd year TPI motors (Firechickens, Camaros and Corvettes) for sure---at least that's how the General spec'd it........you might still have some older motors in trucks or ??? where people wouldn't notice)

yep, fat fingered that one.