3758021 head

[GreenEyez93274]

I recently was on Facebook Marketplace and saw an ad guy selling 348 block (011), crank and heads. After looking at the heads I was trying figure out casting numbers. Never seen that number and searched the fourm for that number also. Nothing came up. Is that truck head?

 

[Don Jacks]

I suspect so.Check that block as it could be a double notched.If those heads are like the 702's that came on truck engines of the era,they make good anchors for your fishing boat and that's about it.

 

[oldskydog]

Yes, it is a truck head. Here's something from my notes that I posted some time ago:

"I was re-organizing my reference library (no Phil, not organizing my shopno1, when I discovered a truck parts catalog that I had forgotten I had. I bought it a long time ago thinking it would cover light duty trucks, but it is a heavy duty truck catalog covering 1 1/2 ton through 2 1/2 ton 55-66 and includes series 60 and 80 trucks with 348-409 engines.

It contains the latest version of the parts available in 66 and I was surprised to find that some obsolete parts like the 56 265 block (casting 991) was still available in 66....probably just left over stock.

The crate engine assemblies and fitted blocks listed were the 655 for 348's and 656 for 409's....no surprise there. What I did find interesting is the 0.269 section for heads. I have seen quite a few heads with casting numbers that I have never been able to identify. Here are the listings:

58 All (348) (cast 3758021) Part # 3758742

59-61 All (348) w/valve rockers, studs (cast 3815857) 3815856

62-65 All (348, 409) w/valve rockers, studs (cast 3819333) 3820640**

** NOTE: Exhaust valve rotator, 3819334, is used with this head assembly in late 62 production. When using this head assembly as replacement on early 62 production models, the old exhaust valve rotator, 3735275, can be used, but valve spring shim, 3764539, must be used to obtain the correct valve spring height.


I have seen the 021 head with a late 61 casting date of A361. This head must be cast with the cooling passages undrilled and is probably the truck version of the 256 casting service head for the early 58 blocks.

I have a picture of the 857 head and it doesn't appear to have the deeply cut exhaust valve rotator seat like the 333 head does. Both heads use the same valve springs, but the early rotator (58-62) is 13/16 thick and the 333 head rotator is 7/16 thick.

I believe the truck heads are as follows:

58 first version without spark plug cooling same as car ? casting 3732791
58 first production version with spark plug cooling casting 3756265
58 service head with spark plug cooling passages but not drilled 3758021
59-61 production head with spark plug cooling 3764702
59-61 service head 3815857
62-65 production and service head with combustion
chamber 3819333


Anybody have an earlier edition of the truck parts manual for verification?"

 

[GreenEyez93274]

Block is double notch but says it 60 over already. Crank is underside also. If block wasn't 60 over i might get it.

 

[427John]

No mention of the 3815643 head in the catalog?

 

[oldskydog]

No mention of the 3815643 head in the catalog?

No, this is a 66 pub so it probably represents only what was still available in service at that time. Since the 643 was apparently short lived and was replaced by the 333 I wouldn't expect it to still be available.