block and head codes

[David M.]

I have a 68, 327 roadster. My son has been deciphering the #s and codes for me. He has determined the block to be correct for the car. Cast dates and partial vin are present and accounted for. The suffix code is V0306HE = Flint, March 6th(April built car). Whats the "HE"?
Next, the heads are not orginal to the car. The previous owner claims they are "Power-Pack" heads? They are 338452s,(452s),60-67, 283ci,60cc chambers. Date says H256= october 25, 1966. Question is on the front of the right head (and rear on left) there's a raised rectangle with a pyramid on top(located where a camel(s) hump would reside). The number 1131 is stamped in the rectangle. What is this symbol and what are the numbers? Power-Packs? Thanks. Dave and Steve.

[Joe L.]

Re: block and head codes

Dave-----

I know of no heads of GM casting #338452 or, even, of '452' for the last 3 characters. If the heads have a "triangle atop a rectangle", though, they are what is known as Power Pack heads and they were used during the 57-65 period for 283's and lower performance 327s. There were several different casting numbers that used this symbol, though. The "1131" is likely a rebuilder's mark which was added post-production.

The "HE" is the suffix code used for 1965-68 base engine 327's in Corvettes. These were 250 hp for the 1965 model year and 300 hp for 66-67. 1968 Corvettes with small blocks never used heads which were identified by the above-referenced casting symbol. All 1968 Corvette small blocks used the "double hump" casting symbol.

[Joe L.]

Correction

The "HE" suffix code was used for 1965 through 1968 for base engine small blocks in Corvettes. Also, Power Pack, "single traingle" heads were used through 1967, although not in Corvettes after 1964.

[Verle R.]

Re: block and head codes

Dave,

The HE is the build code. In 1968 Corvette it means:
300 HP 327 Cubic Inch
1 4 barrel carburetor
manual transmission

The heads you describe are 283 "power pack" heads. The pyramid was used for years on heads with 1.72" intake valves and 1.50 exhaust, on 283 engines in many cars.

Your engine should have head casting number 3917291 with "double hump" on each end. Casting dates should preceed the 0306 date by no more than six months.

The number stamped in the end of the head may have been placed there by a rebuilder, not normal GM.

Good luck

Verle

[David M.]

Re: block and head codes

Thanks all for the help!