heads

**jiveass** · 02-06-2010, 07:27 AM

I am currently putting together a 350ci for my vette. According to the block casting, the engine came from a '70-'76 chevy, didnt specify on mortec. The question at hand is about the heads im going to use. I have a pair of 327 heads from my dad for free. The casting numbers are 3782461, which shows to be from a 1964-1966 327, not specifying which car. The date code is k95...which means november 9 of 1965. Im trying to to find out which valve size i have, 1.94 or 2.02 and which hp version of the 327 they came from. It could be the 250, 275, or 300hp engine. The corvettes came with 300-375hp engines with a different version of these heads, but i doubt i have the vette heads since the guy my dad got em from said they came off of 65 chevelle. Can anyone tell me how to find out which heads i have?

**Firebirdjones** · 02-09-2010, 08:37 AM

If it has factory screw in studs with guide plates, (meaning they haven't been added) then you have genuine 2.02 heads, because that's the only way they came.
GM used standard 1.94 valve heads on all the 327's up through the 300 HP models, which had push in studs and no guides. After that, they were all 2.02's with screw in studs and guides. (ie: 325hp, 340hp, 350hp, 365hp, and 375hp).

All of the 461's had the same combustion chambers though, at 64cc.

**jiveass** · 02-09-2010, 11:36 AM

Originally Posted by Firebirdjones

If it has factory screw in studs with guide plates, (meaning they haven't been added) then you have genuine 2.02 heads, because that's the only way they came.
GM used standard 1.94 valve heads on all the 327's up through the 300 HP models, which had push in studs and no guides. After that, they were all 2.02's with screw in studs and guides. (ie: 325hp, 340hp, 350hp, 365hp, and 375hp).

All of the 461's had the same combustion chambers though, at 64cc.

any way to tell what car these came from? or would i need the engine casting as well to determine this?

**Firebirdjones** · 02-09-2010, 02:03 PM

Originally Posted by needls1again

any way to tell what car these came from? or would i need the engine casting as well to determine this?

Although they are year specific,,,the actual car would be hard to determine. They put 327's in everything back in the day, and they all had their own HP ratings, with either 2 barrels or 4 barrels. Starting with a seldom seen 250 HP version in the 62-63 vette that did have a 4 barrel. The 275 HP versions were found in Impalas with a 4 barrel as well as 300hp versions found in Impalas with a 4 barrel.

You could break it down a little bit by HP ratings if you knew which head you have (1.94 verses 2.02)

The 1.94's as I said were installed in anything 300hp and down. That could be anything from Impala's, vette's, nova's, and even chevelles. Lower HP versions were installed in camaro's, usually as 2 barrel versions in your base model camaros, and even Rally Sports. The camaro came out in 67, and the standard SS engine was the new 350/295hp engine for that year, as it was standard for all 67-70 SS camaro's. Rated at 300 hp late in 69 and through 1970 though.

The 2.02's were on all 327's from 325hp on up. And those HP ratings varied depending on application. The 325hp version was found in the early chevelles, which was the same as the 350 hp version later found in the 66-67 novas. The 340hp version was a solid lifter cam that first appeared in the vette in 62. Same engine was raised to 350hp in the 66 vette. The 365hp version was also vette exclusive and was the carb version of the fulie 375hp version, also a vette exclusive.

Knowing that your heads are dated November of 65,,,,that would mean you actually have early 66 heads. Remember the production year started in August of the previous year. So your heads are about 4 months into the 66 model run.
With that said, you would have to determine which valve size you have (screw in studs and guides) to tell you if you have 300hp and down heads,,,,or 325 hp and up heads.

In 66 the lower horse heads could have been put in an Impala, a Vette, or a nova. As they all had optional 275/300 hp 327's that year.

On the higher HP heads (325 and up) in 1966 that could have been Nova, Vette, or chevelle. Impala's never got a high horse 327.

Does this confuse you even more???

**jiveass** · 02-09-2010, 03:03 PM

no confusion really...but my dad did say that the guy he got em from said they came from a chevelle..but i was just tryin to be sure about it. guess ill check the studs when i get home..

**Firebirdjones** · 02-09-2010, 03:17 PM

Sorry, didn't mean to throw all that out in one shot. The 327 was such a versatile engine back then with HP combo's all over the place.

If he is certain they came from a chevelle originally, then I'd bet money that they are probably 1.94 valve heads with push in studs and no guides.
I only say that because the amount of 327/325hp chevelles build in 65-66 are extremely few (in the 100's I would guess). Compared to the thousands built with lower horse 327's and small valve heads, the odds are in that favor.

That 327/325hp engine was what became the L-79 in 66-67 for the nova and rated at 350 hp. But you could get it in chevelles from around 65 up through the 68 model year. Even if you added all the production years together for the chevelle and that motor, you'd still be in some rare company.

**jiveass** · 02-10-2010, 04:04 AM

Originally Posted by Firebirdjones

Sorry, didn't mean to throw all that out in one shot. The 327 was such a versatile engine back then with HP combo's all over the place.

If he is certain they came from a chevelle originally, then I'd bet money that they are probably 1.94 valve heads with push in studs and no guides.
I only say that because the amount of 327/325hp chevelles build in 65-66 are extremely few (in the 100's I would guess). Compared to the thousands built with lower horse 327's and small valve heads, the odds are in that favor.

That 327/325hp engine was what became the L-79 in 66-67 for the nova and rated at 350 hp. But you could get it in chevelles from around 65 up through the 68 model year. Even if you added all the production years together for the chevelle and that motor, you'd still be in some rare company.

very usefull info...what ill probly end up doing in measuring the valves as well as checkin the studs...either way i will still use the heads as they are probably way better than the heads that are on the engine right now...firebird jones, you are always a great help in this department. dont be surprised if i pm you with more questions.

**Firebirdjones** · 02-10-2010, 09:06 AM

Feel free.

Not sure what year car these are intended for, but just a heads up that some people don't consider.....

The hump heads from 1962-1968 do not have any accessory holes, meaning no way to bolt later model brackets to the heads for alternator, PS pump, AC, etc....

If these are intended for a later model car, you will have to locate the early model accessory drive setup.

GM did make "hump" heads with accessory holes from 69-72,,but they are much harder to find.

**jiveass** · 02-10-2010, 09:21 AM

yea i have no accessory holes in mine...but my dad has so much crap layin around from old cars im sure i can find somethin to make it work.

**dirttrax** · 02-10-2010, 09:42 PM

Originally Posted by Firebirdjones

Feel free.

Not sure what year car these are intended for, but just a heads up that some people don't consider.....

The hump heads from 1962-1968 do not have any accessory holes, meaning no way to bolt later model brackets to the heads for alternator, PS pump, AC, etc....

If these are intended for a later model car, you will have to locate the early model accessory drive setup.

GM did make "hump" heads with accessory holes from 69-72,,but they are much harder to find.

Yeah they did make some with casting 291 but like he said are not as easy to find. They do exist and the last three sets i bought the people had know clue what they were, they just knew they werent 300 horse heads because they didnt have 461 or 462, so I just smiled and bought them.

**Smittro** · 02-10-2010, 10:21 PM

Originally Posted by dirttrax

Yeah they did make some with casting 291 but like he said are not as easy to find. They do exist and the last three sets i bought the people had know clue what they were, they just knew they werent 300 horse heads because they didnt have 461 or 462, so I just smiled and bought them.

Not surprising most folks can't tell the differance between one SBC and another either.. Camel back or "hump" 2.02 heads are usually hard to find no matter what the year...

**jiveass** · 02-11-2010, 03:33 AM

Originally Posted by Smittro

Not surprising most folks can't tell the differance between one SBC and another either.. Camel back or "hump" 2.02 heads are usually hard to find no matter what the year...

well these have the humps, but i read that it could be 2.02 or 1.94

**Firebirdjones** · 02-11-2010, 04:30 AM

Originally Posted by needls1again

well these have the humps, but i read that it could be 2.02 or 1.94

That is correct. Camel humps came in both versions, 1.94 and 2.02 valve sizes.

**Smittro** · 02-11-2010, 05:56 AM

Originally Posted by needls1again

well these have the humps, but i read that it could be 2.02 or 1.94

Originally Posted by Firebirdjones

That is correct. Camel humps came in both versions, 1.94 and 2.02 valve sizes.

I believe the humps are round on the 2.02 (like a mickey mouse hat ears), and the humps are squared on the 1.94's... Bare with me guys I,m old and have'nt looked @ or messed with a 350 sbc in a decade or so..lol Most of what I've been doing involves 4 valve heads on the Chevrolet (X-engine) 60* TDC v6 with 2.5x2 port openings, with forged factory rods and more power stock (200-215hp @5200 N/A) than most stack 350's from the same era (early 90's) flow is not a prob lol..

**jiveass** · 02-11-2010, 07:35 AM

this link shows what the humps look like. check it out.

http://www.chevellestuff.com/qd/head...ng_by_year.htm

**Firebirdjones** · 02-11-2010, 07:38 AM

They all used the same casting, or mold. They even used the same casting numbers.
The difference came in the machine work as per which HP engine the head was intended for.
Any 327 rated at 325 hp and up got 2.02 intake and 1.60 exhaust valves as well as screw in studs and guide plates.
327's that are rated 300 hp and down got the 1.94 intake and 1.50 exhaust valves with push in studs and no guide plates.

It's the same way for 350's. Which came out in 67 along with the 327. 350's then were rated at 295 hp which jumped to 300 hp in 69-70 for the tame hydraulic camed version.
But in 1970 the 350 with the solid cam rated at 360/370hp got the larger valve 2.02/1.60 heads with screw in studs and guide plates.
By this time the heads used a different casting number and had threaded accessory holes for a different bracket mounting system.

**pajeff02** · 02-11-2010, 08:18 AM

OP: Is there any concern that the older heads do not have hardened seats?

**Smittro** · 02-11-2010, 08:29 AM

Originally Posted by pajeff02

OP: Is there any concern that the older heads do not have hardened seats?

I think this will show upon examination. Soft seats if I remember correctly, show up on used heads if the valves have sunken into the seats or a crack has appeared between the 2 seats... I always thought it was the seat angle that caused most of the head issues with the older sbc heads..

**pajeff02** · 02-11-2010, 08:36 AM

Originally Posted by Smittro

I think this will show upon examination. Soft seats if I remember correctly, show up on used heads if the valves have sunken into the seats or a crack has appeared between the 2 seats...

The OP didn't appear to know their history, so there is no telling when they were last on an engine. I just wanted to point this out as that can be a concern if hardened seats are not installed as part of the build. I run a lead additive in our Oldsmobiles and Buicks just to err on the side of caution.

**jiveass** · 02-11-2010, 09:04 AM

Originally Posted by pajeff02

The OP didn't appear to know their history, so there is no telling when they were last on an engine. I just wanted to point this out as that can be a concern if hardened seats are not installed as part of the build. I run a lead additive in our Oldsmobiles and Buicks just to err on the side of caution.

well i planned on having these heads re-conditioned at a machine shop... so whatever needs to be done will be done...i guess the main purpose of this thread is to find out where these heads come from.