My 327 Rebuild...Question

I now have my 327 tore down, and the block is in for cleaning, testing, boring, cam, etc.
Next will be the heads, and I have a quesion here.
They are numbered 3890462 and according to the info I have looked up on the internet they are listed as having the 2.02 valves.
Did ALL of these have the 2.02's or did some have the 1.96's?
I am not a pro, and don' have a way to accurately measure them, as I have not started on the heads yet, and they are still in place.
If the heads get too expensive to redo, I am considering just buying some that are alread re done.
Thanks in advance for any help
Cheers,
Bob

 

Some have 1.94 valves, more often than not really. Not a bad thing, I'd rather redo a set of 1.94's to 2.02 if I were having them rebuilt than starting with 2.02's. Nice looking and performing heads. Cl***ics. You can check valve size with a steel rule. 1.94's will be a little under 2 inches, 2.02's will be a little over.

 

462s are great casting heads. Freshen em up and run them!!

 

Regardless of the valve sizes.. It would be a good idea to have the hardened seats installed for unleaded fuel.

 

These are good heads, non knowing the pedigree, get them checked by a machine shop for cracks. A few extra bucks but worth it. A simple way to know what valves you have is to measure them with a caliper if you have one.

Bob

 

A real quick way to tell if they're 2.02 and 1.60 is the thin gap between the diameters.. The smaller 1.94 and 1.50 valves, the gap would look a little farther apart.

 

Thanks all for the inputs.
I took a small tape and they look like they are NOT 2.02, but the 1.94's.
I am wanting to get about 350hp out of this engine, using a cam, etc.
What basic performance will be the difference between the 1.94's and the 2.02's.
This is strictly a driver that I want a little at***ude out of.

 

350 hp is possible with those heads. You'll get better low end torque with those for around town cruising. An Edelbrock air-gap intake with a Holley 750....... No problem!!

 

For a driver, it's not a big deal.
you would be better of spending your money on headers, cam kit, intake and carb...before you worry about big valves.
They matter when the headers are open,and its winding tight.

 

750 cfm sounds waay over carbed to me.. make sure to do some build math so that thing will make optimum power.

 

Your right! The L-79 327/350 came with a 585 or 575 cfm Holley carb... So your better off with a 600 cfm with vac. secondaries...

 

1.94, 2.02 there's not that much difference in performance. Less is more with the carb, I've gone as high as 650 CFM, but as others before and after me, have drowned their mouse with a 750 or 850.

Bob

 

NO need for hard seats

So why did the 302 Z engine come with a 780 cfm carb

 

I found out about the HAMB originally via an excellent thread about these heads.
Here is the link:
http://www.jalopyjournal.com/forum/showthread.php?t=196227

 

Here were his 2.02/1.6 vs. 1.94/ 1.5 pics. Excellent thread that is worth a read.

 

with that engine they expected you to start the car , immediatly rev it to 6500 rpms, keep it there till you reached your destination and then shut the car off

 

Yessirree bob!

(I'm guessing he meant 780cfm not 78)

 

........ That's with a 5.56 gear out back.

 

the L79 motors had 1.94 intakes in them stock. i also ran 1.94's on the dirt car. they give you torque that is what you need. if you must have bigger valves use the 1.60 exhaust. they work good with the 1.94 intakes.

the hard seat myth is just that a myth. if the seats are good then just use them. i have done alot of heads and never had to use the hardened seats. but you do have to have good valve guides. i like to bronze wall them to rebuild them. do not replace them with new. that will get you into more trouble then a little with valve location. do use stainless steel valves. do use new z28 valve springs.

carb size don't go bigger then a 600 cfm with vac.secondaries. do rework your dist. at 10deg and to start to move at about 1000 rpm and it should total out at 28 deg. at 3200.

 

I am pretty sure all L-79 motors had 2.02/1.60 heads

 

great heads had a set in the 70es the machine shop i used at the time stated that it was more importent to put larger exhaust valves than intake . with screw in studs and guids they made a lot of horse power

 

Great pics....Helped a bunch. My valves are definately NOT 2.02's.

 

I'm running a 327 with the 1.94's now. Had the heads reworked, guides, and then had the hardened seats put in. Reason? you can get by with the std seats for a long time, unless you drive it distances and keep it turned up. With the seats, they will last no matter what you do. I looked at other heads, decided to spend the money on these and am glad I did. Like the other guys say, they look cool.
cooger

 

all the L79's i have seen and worked on had 1.94 heads. even my 66 L79 vette and the numbers match.

i also used standard seats in my race motors never had a problem. it is the guides that ware then when the valves are rattling around in the worn guides they beat out the seats. it is not a seat problem.

 

i have a pair, one has 202's and the other is 194"s, the 202 head is fly cut around the intake valves, the 194 head is not. i dont know if there all like that or not.

 

I believe the early 327 1966 vettes had the 461 double hump heads and were available in 1.94/1.50 (300hp) or 2.02/1.60 (350hp). Then late 327 1966 vettes came with 462 heads and had either 1.94/1.50 (300hp) or 2.02/1.60 (350hp).

 

Sure, no problem. Check out that original thread, if you have not already, it was really a good one.

 

The perfect carb for you is not a 750 ,I had one and mixture screws did not work ,Ran great .But was rich ,I then downsized to a 670 Holley ,Perfect ,Mines a 69 327 ,202 heads and a 292 cam with 454 lift .And Im around 325 -330 horse .And also Im 30 0ver ,

 

My '56 has a 327 with 462's and my '65 Chevy II has a 327 with 462's. I like 'em. Both are 1.94's, as were the vast majority of the 462's. You gotta remember they built lots of 300 hp 327's

 

l-79's have 2.02's and the 1.94's will run better on the street,less valve shrouding and more port velocity.