Topic: Differences in K, A,C- code engine blocks, 1965,1966

[ceswert]

Are there differences in the A,C and K code 289 blocks? Differences include design, specs, materials, manufacturing and anything else. Why would Shelby use K code blocks as opposed to other codes? Thanks.

[bryancobb]

Seems like I remember reading somewhere that casting numbers were the same but ones that were to become K-Codes were "hand-picked" and were ones that were the "best-of-the-lot" and ones whose cores were positioned just right during casting, which resulted in more uniform wall thicknesses, etc.

[tomtri66]

Seems like I remember reading somewhere that casting numbers were the same but ones that were to become K-Codes were "hand-picked" and were ones that were the "best-of-the-lot" and ones whose cores were positioned just right during casting, which resulted in more uniform wall thicknesses, etc.

+1  Once they were "hand picked" they were marked with orange spray paint for identification.

[tomtri66]

Are there differences in the A,C and K code 289 blocks? Differences include design, specs, materials, manufacturing and anything else. Why would Shelby use K code blocks as opposed to other codes? Thanks.

Shelby ordered K-code white fastbacks from the factory with no options in 1965 as a starting point for GT350s.  Hence the K code engines were the basis for the 306hp shelby 289 build.  Shelby added Cobra high rise aluminum manifold, 715 Holley carb, tri Y headers and exhaust to boost the K code engines rated 271 hp to 306 hp.  Blocks and cranks were not different except for the "hand picked part" Brian mentioned.  Rods (casting the same but machined for larger rod bolts), pistons, heads, main caps, and balancing etc are different in the K code, however.

[Jack65K]

I have heard about the blocks being hand selected as "the best of the lot" but I am not sure that has been verified.  I thought the block castings were the same and the differences were in what went into building up the block with the heavier main bearing caps, cam, heavier rod bolts, etc.
Jack

[J_Speegle]

Shelby ordered K-code white fastbacks from the factory with no options in 1965 as a starting point for GT350s.  Hence the K code engines were the basis for the 306hp shelby 289 build.  Shelby added Cobra high rise aluminum manifold, 750 Holley carb, tri Y headers and exhaust to boost the K code engines rated 271 hp to 306 hp.  Blocks and cranks were not different except for the "hand picked part" Brian mentioned.  Rods (casting the same but machined for larger rod bolts), pistons, heads, main caps, and balancing etc are different in the K code, however.

For 65- 66 Shelby ordered standard interior K code fastbacks with the export option - starting in 67 the ordering and fulfillment request changed requiring some fun paperwork exercise to produce the starting platform they were looking for.

After a short period in 65  Ford and San Jose was making many of the changes to change the normal K into a Shelby engine. The idea of Shelby doing all the changes is an "oil wife's tale" suggested by a few published early pictures.

Carb was a 715 cfm for four speed GT350 cars in the early 65-67 years

Bottom line is that you can take a standard 289 with the right casting numbers and dates - add the K code main caps and you have a K code engine (you can choose to replace the orange paint  that would come off when you hot tank the engine and that no one will see once installed)

[tomtri66]

Carb was a 715 cfm for four speed GT350 cars in the early 65-67 years

opps my bad.  Absolutely should have said 715 cfm. 

[Greg45]

Just tore my engine down this spring.  The block appears to be the same as other 289s except the VIN is stamped on it.  There was a white HP on the back of the block but obviously no way to see if it was hand picked.  The main caps, on the other hand, are obviously heavier.  The crank has been polished on a rear balance weight and I understand that it was examined to verify that the casting has sufficient Nodularity.

Greg
65 2+2 GT, K code, Dearborn build date June 10 65, delivered June 20, 65

[J_Speegle]

Just tore my engine down this spring.  The block appears to be the same as other 289s except the VIN is stamped on it.  There was a white HP on the back of the block but obviously no way to see if it was hand picked.  The main caps, on the other hand, are obviously heavier.  The crank has been polished on a rear balance weight and I understand that it was examined to verify that the casting has sufficient Nodularity.

Greg
65 2+2 GT, K code, Dearborn build date June 10 65, delivered June 20, 65

Sounds like you might have a K code bottom end - if the main caps don't have big numbers on them

[Greg45]

Sounds like you might have a K code bottom end - if the main caps don't have big numbers on them

I purchased the car new in 65, and it has never been apart, so I'm pretty sure it has the K code bottom end (and heads, and exhaust, and distributor, and .....  )  I picked it up at the rail yard, so it never saw the dealership.

The water pump and alternator are not original because I replaced them in the late 60's.  I always wanted to hot rod the motor, but never had the money.