Chevy straight six head numbers

Anyone help decoding these Chevy / GMC head numbers for a 235 stright six?
3838848

I could not for the life of me find any match in my resources.

thanks,
N

 

You have a late 50's to end of production 235 head.

the numbers are available on the Inliners web site, but its down at the moment.

 

check for just the last 3 numbers "848"

 

It isn't on the list for the chevy 6's. It must be a GMC.

 

Nope - not on my GMC list.

"848" is a Chev casting number.

 

"848"=`58-`62 thats a desirable head.

 

The only list I have is the one in the Patricks catalog. Are there more numbers than what he lists??

 

848 is the good one. The holy grail of 235 heads

it's 383 6 848

just walked three miles in the snow barefoot to check. uphill both ways, too

 

I think the 848 head is for the 261 engine too. I might be wrong.

 

Nope, your right. 261 also.

 

I think it goes back before '58, I've seen at least two '56 engines with them.

 

indeed, it's the highest compression stock head. good stuff.

 

The first '848' heads came with 1956 passenger cars and 235s had 8.0 cr per manual specs. After 1958 they were listed with 8.25 cr, which indicates they had factory milled heads and possibly decked blocks by about 0.020

They got smaller chambers with highest compression ratio of any early 6 heads and also have a higher nickel content, helping to prevent cracks from heat stress.

Most guys mill them to increase ratio further.

Fits with all 235 and 261 blocks.

The corvette from 1953-55 used the smaller 848 chamber casting first, but these heads had a different casting number then.

 

Needs steam passages drilled for a 235 head to work on a 261

 

Also use different head bolt torque sequence for 261 blocks, for the same reason.