[Lifer]

Hey guys,

I'm looking to make some online friends who have knowledge with regard to these engines. The guy I bought this engine from pulled it out of a 1975 Firebird, it seems to be the original motor, but you never know what has been done over the years. Here is the information I have so far.

Engine Code: F052OCJA
Vin code: 24N156969
These two numbers (above) are on the distributor pad.

The number 328575 is on the passenger side, which pretty much confirms this was a passenger car engine..

I a bit confused on the horse power rating though, see I also have a 1968 L6 from a Nova.. would these two engines be the same with regard to horsepower/torque? if not, why? Does it have something to do with the pistons/bore??

One thing I have noticed which is different, according to Rockauto, is that each balancer differs in width and weight.. (see below)

Nova
Diameter; 6-3/4"; Width: 1-1/2"; Weight (lbs.): 7.5

Firebird
Diameter; 6-3/4"; Width: 1-7/8"; Weight (lbs.): 8.4


The 68 is currently in my G20 van and it rocks the nation, I'm wondering if the Firebird engine will do just as well in a K10 pickup... also, will this engine be able to push snow? I don't see why not.. Just wanted some advice from the elders and/or pros.

Also I have a 292 inline which I'm thinking about selling, it came out of a 1980 p30 I think, just wanted to put that out there.. and I will be looking for a 4bbl intake/header/194 head/ if anyone has anything, let me know..

Thanks
Chicago IL.

[Mr. P-Body]

The short block portions are virtually identical.

The "main" difference between the two generations would be the head and manifolding. The '75 is known as an "integral" head, where the intake manifold is cast integrally. A portion of the exhaust is, as well. These heads are notorious "crackers". The earlier engine has separate manifolds, like the 194 head you're asking about. The HP ratings are measured differently between '68 and '75. '68 was "gross brake" HP and '75 is "SAE Net" HP. GBHP is measured at the flywheel with nothing "attached" (the dyno is the only "load"). SAE Net is at the tailshaft of the trans, "in gear" with accessories operating (power steering, A/C and alternator). The Net rating is probably more realistic.

We've done several "hot" Chevy 6s over the years. Clifford Performance (Cal) still offers a significant number of performance "goodies" for the engine, including the 4-bbl. intake.

1.94 intakes, 1.6 exhausts (small block length), small block springs, retainers and locks, all help. Some porting and a solid cam, it can make 300 HP at 256 CID. I believe Harland Sharpe still offers roller rockers for it, too. Upgrading the connecting rods can also help. If you knew where a Pontiac OHC 6 was sitting in the mud somewhere, the rods are the same width/length, but much better forgings. In olden times when we did "Hobby Stock" circle track 6s, that was the rod of choice. There should be an aftermarket H-beam available.

Cool engines, aside from the "drone" 6s make (some like it). We have a customer with a 250 Pontiac OHC making 325 HP (pump gas, still "hydraulic"). He calls it "The Angry Hornets".

Jim

[Lifer]

Well, I'm happy to announce, yesterday I went out and bought a 1981 C20 equipped with a 292 and POWER steering! The truck has been garage kept and very well maintained since birth. I am the second owner.


Mr. P-Body
Both the 68 and 74 engines are non integral, with points distributors. I was just wondering if there was a difference in HP.

[Mr. P-Body]

Lifer,

Agreed. '74 was the last year for the "older" head design. You say "'75 Firebird". And the '75 had HEI.

PAX

Jim

[Lifer]

I'm thinking it was an early month in 75 when this car was produced. The 1975 Firebird engine is a non-integral, with a points distributor.

[Mr. P-Body]

Not the THREE (limited sampling, to say the least) I've seen over the years. '74s? Yes. '75s were the same as Camaros (what I've actually seen, I''m not a "book hound"). Damn rare car, 2nd gen Firebird with a 6... I believe it was a "delete" option.

Jim

[Lifer]

In any case, would the horse power rating be the same between a 68 and lets say a 74?

I'm just wondering why the balancer is different in both weight and depth..