I pulled the intake tonight to fix a pesky leak at one of the exhaust heat xover passages. One thing that surprised me was the wierd "can" in the lifter valley for the PCV system...

Back to the question. The heads are casting #3774682's. From what I've researched this means 1960 - 1964 283/327's, with 70cc chambers.

What HP level would this translate to...? The low or mid-HP 327?

The can under the intake is the PCV oil separator can.

Those should be for a 195hp/283 and a 210hp/327, I'm thinking what I call power pack heads but may be off here?

Is there a triangle in the middle of the flat rect. boss on the ends?

If so, PP heads. 1.72"/1.50" valves in them.

pdq67

DO NOT, DO NOT, DO NOT remove the "can" under the manifold!
As mentioned, this is an oil seperator, its intended purpose is to seperate vapors from the oil inside the crank case. The vapors are then sucked out that hole in the rear of the top of the block and through the PCV valve/hose. In 1968, the blocks were changed and this hole was removed from the rear of the block. Crankcase ventilation was achieved with holes and a PCV valve in the valve covers. The factory valve covers had a baffle at this hole for seperating the vapors. Consequently, on 68-later small blocks, you can no longer use plain "no hole" valve covers. This was the beginning of all the extra plumbing under the hood. :sad:

In 1965, all Corvette, Chevelle and passenger car 327s received double hump heads, 461 castings.

If this is a 65 engine in a Chevelle, someone has changed the heads at least if not the entire engine.

Truck engines probably had power pack heads.

What are the casting number, casting date and build codes stamped on the block.

He didn't mention 1965 or 'Vette??

pdq67

He didn't mention 1965 or 'Vette??

pdq67

Actually, the title to his post is "65 327 question".

Since he lists a 65 El Camino in his signature it may be a safe assumption that he has a 65.

He also did not mention a truck or passenger car but 65 they all had 327 as an engine.

Actually, FWIW, there were 2 versions of 283's - a 2bbl and a 4 bbl (Power Pack), a 250 hp. 327 with the non-double hump heads and Rochester 4 bbl., 300 hp 327 w/a Carter AFB carb, dbl humps & small intake valves and the 350 L79 with large intake valves and dbl humps - all available in a Chevelle/Elcamino of any body type. These and the 6 cyl. engines could all be bought with a PG, 3 spd man. or 4 spd. - except the L79 which was with a 4 spd. only. All 327's came with 12 bolts in 65.

Gotcha Verle, my bad.

Are the heads PP jobbers??

Verle, I just HATE to see 'Vette mentioned b/c some guys think their parts are worth more money to the 'Vette crowd is all.

And don't forget about the 365hp carb'd and 375hp FI'd 'Vette engines that came w/ the big valve -461 heads on them. The other 327's came w/ the medium valve double-hump heads on them if I remember right like the 340hp engine.

I don't know what head came on the '67 325hp/327 but probably can hunt it up in 5 minutes? Probably a big valve -462 or -291?

pdq67

I just threw out a pair of -520 PP heads yesterday. Figured considering their age, lack of hardened seats, and the possibility of cracks around the exhaust, these weren't worth the time/effort/expense to rebuild.
Bought a fresh pair of -601 305 HO heads instead. Chambers cc'd at 55cc.
With TRW forged flattops, a .025" deck, and .015" shim gaskets, they should work real well on my 292 project.

Actually, FWIW, there were 2 versions of 283's - a 2bbl and a 4 bbl (Power Pack), a 250 hp. 327 with the non-double hump heads and Rochester 4 bbl., 300 hp 327 w/a Carter AFB carb, dbl humps & small intake valves and the 350 L79 with large intake valves and dbl humps - all available in a Chevelle/Elcamino of any body type. These and the 6 cyl. engines could all be bought with a PG, 3 spd man. or 4 spd. - except the L79 which was with a 4 spd. only. All 327's came with 12 bolts in 65.

According to the AMA spec sheets I have (I can scan and post a few pages if anyone needs to see it) ALL Chevelle 250hp and 300hp 327s used the same heads with the 1.92/1.50 valves and the 350hp 327 used the same heads but with 2.02/1.60 valves. The biggest difference listed between the 250hp and 300hp engines is the carb (Roch. vs. Carter) and single and dual exhaust set ups.

Also, the L79 wasn't 4-speed only, it was manual transmission only. It came standard with the heavy duty 3-speed, the 4-speed was optional.

Not all '65 327s came with 12-bolts. I've owned a numbers matching authentic '65 L79 car that came with a 10-bolt posi. Personally, I think this was only due to a strike at the axle plant and 327 cars were all SUPPOSED to get 12-bolts, but I know for a fact that at least some did not. It is noteable that the car I mentioned was an L79 car not just any 327. This same strike at the axle plant caused some weird stuff on my current L79 car too since it is thoroughly documented to have been built with a 12-bolt open rear (codes on the axle, dates on the axle and the POP confirm it is the original rear) yet it has a posi which is documented on the dealer invoice as being installed at the dealer. In talking with the man who sold the car new to his nephew, a strike at the axle plant caused a shortage of posi axles when the car was built so it was simply built with what they had and shipped and the posi was installed at the dealer. This same axle shortage probably explains the other L79 car I had which had a 10-bolt since it had been built at the same plant but a little later in the month. I don't know how long the strike lasted or how widespread of an impact it made.



I don't know what head came on the '67 325hp/327 but probably can hunt it up in 5 minutes? Probably a big valve -462 or -291?

pdq67

The '67 L79 I believe used 462 heads (not sure about 291s, don't know why not since they are basically the same). They definitely had 2.02/1.60 valves.

3774682....60-64...283/327......70cc chambers
3774684....62-64...327..........75cc chambers
3774692....58-64...283..........60cc chambers


according to http://www.mortec.com/castnum.htm in the SBC head section.....

It's a late Sept. car, so I doubt they'd be using up '64 castings that late in the '65 build year. I'm guessing a head swap/rebuild was in it's history.

a 250 hp. 327 with the non-double hump heads and Rochester 4 bbl.

I will respectfully disagree with you on the 65 250HP 327.

I believe the 250 HP engine also came with double hump heads.

That is my memory from back then, also backed up by a GM parts manual:

65 327 (exc Sp H/Per.) (ident No 3782461) part # 3817681
65 325 w/Sp H/Per (ident No 3782461) part # 3853608
both priced at $48.40 for the assembly.
It does not distinguish between 327 except for Sp H/Per. (L79)

Everything else you said is correct.

1962-1964 250hp/327 used the small valve 283 "power pack" heads. '65 250hp 327 had the 461 "camel back" heads.

BTW.... I'd like to buy a few of those assembled 461 heads for $48 ea. LOL

Big valve -461's, me too, but I have a big valve pair out in the garage now gathering dust along w/ my big valve -291's.

pdq67.