283 & 327 w/4 bolt mains
 

Does anyone have any original GM 4 bolt main caps for a small journal crank? These are the straight bolt type, not splayed.

R U talking about 2.300 inch? Like pre 1967

The small journal block never had OEM 4 bolt main caps, if you have a early block with 4 bolt main caps they are aftermarket pieces. Program Engineering, Milodon, Summers Brothers are some of the suppliers for these pieces. Your best bet would be to get a machine shop to look at your motor and help you out. Posting some pictures of the pieces your talking about would be helpful.

That is why I ask about the actual small journal size 283. 307, 327. Those are not desirable for hot rodding. 4 bolt only appeared when the journal went to 2.400

1959 283

Not originally 4 bolt.

Go Cats.

:thumbs:

This one was.............................not your everday production block, but a GM block anyway.

GO CATS!

I went to college at UNLV and live in this great state. They are number 8 seed in southwest Tourn. I hope that they make it a couple of rounds!:D

I just can't remember a 283 with a 4 bolt. anything is possible though.


Here's the list of all the small block casting #'s

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

140029.....350...80-84...2
330817.....400...72-80...2
355909.....262.....75....2
360851.....262...75-76...2...Monza V-8
361979.....305...78-79...2
366245.....350...78-79...2
366287...................4...Bowtie, Aluminum, siamesed,
straight nodular iron main
caps, 2-piece seal, 4.00-4.150"
bores, 2.45" main journals
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
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
3814660....327...68-69...2
3830944....327.....63....2
3834810....283...64-66...2
3834812....283...62-63...2
3837739....283...58-62...2
3849852....283...64-68...2
3849935....283...65-67...2
3852174....327...62-64...2
3858174....327...64-66...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.....67....2
3896948....283...66-67...2
3903352....327.....67....2
3914636....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
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....350.....69....2 or 4
3951509....400...70-71...4
3951509....400...74-80...2
3951511....400...70-71...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...62-63...2
3970010....302.....69....4...Z-28 Camaro
3970010....350...69-80...2 or 4
3970014....350...70-74...2 or 4
3970020....307...70-73...2
3970024....307...69-71...2
4715111....305.....80....2
6259425....350...69-76...2
10036033...350...........4...Goodwrenc… crate motor, 2-piece rear
seal, "Hecho en Mexico"
10051182.................2...Bowtie, non-siamesed, 3.75" bore
10051184.................4...Bowtie, non-siamesed, 4.00"-4.160" bores
10054727...350...86-up...2 or 4...one piece rear seal, some "Made in Canada"
10066036...350...........4...Goodwrenc… crate motor, 2-piece rear
seal, "Hecho en Mexico"
10066038...350.....94....4...Goodwrenc… crate motor, 2-piece rear
seal, "Hecho en Mexico"
10090511...350.....90....2...LT-5, ZR1 Vette, 375hp
10125327...350...92-up...4...Gen.II LT-1, reverse flow cooling
10125327...350...96-up...4...Gen.II LT-4, reverse flow cooling
10134996.................4...Bowtie, Aluminum, 4.125" bore
2.65" main journals
10153558...350...91-92...4...LT-5, ZR1 Vette, 375hp
10199001...350...93-95...4...LT-5, ZR1 Vette, 405hp
10243878...305...96-97...2...Vortec truck, roller cam, one-piece rear seal
10243880...350...95-99...4...Gen.I crate motor, "ZZ4", roller cam, one piece rear seal
12550592...350...97-up...crossbolted block, Gen.III, "LS1"
12559846...350...98-up...crossbolted block, Gen.III, "LS1"
12560621...350...98-up...crossbolted block, Gen.III, "LS1"
12562174...350...98-up...crossbolted block, Gen.III, "LS1"
14010201...305...80-84...2
14010202...305...80-84...2
14010203...305...80-84...2
14010207...350...80-85...2 or 4
14010209...350...80-85...4
14010280...

I thought the first 4 bolt block was the 4" bore block used for 68 and up 302 and 350. Never in my searching have I ever seen a GM 4 bolt 327 or smaller.

I never saw one either.

Me neither...........................until yesterday.

I've a 265, 3 or 4 283s to of them Nova blocks and a half dozen 327s all small journal and all 2 bolt. Never have seen a 4 bolt from the factory version.

4Bolt main caps didn't happen until 1969 model year. All 350/302 SBC built in the 67-68 model years have 2 bolt main caps. Also hi-perf motors have nodular iron caps where low HP motors have regular iron caps.

Here is a nodular iron hi-perf cap on my 70 LT-1 motor build:

http://i601.photobucket.com/albums/t...LT1maincap.jpg