Mr D.

Hi Guys
Well I’m moving forward with my BB swap out project. I would like everyone’s input or thoughts on what cam and piston set up I should go with. Here are the details:

Block: 3963512, 2 Bolt, 030 over

Heads: 3931063, Closed Chamber, 100.967cc

Intake: 3885069, 1966 Corvette 425 hp. Holley 3310 Carb

Note: While I know the Oval port head and Square Port Intake setup do not match, I have been told by a few knowledgeable people that this combination will work.

The block and heads are going to the machine shop next week and I also plan on having the heads ported and overall updated and made to run better. Nothing extreme. My goal is to have a L72 (from an appearance standpoint) that puts out 400 – 450 hp that is dependable and will run on pump gas. This will be an AC / PS setup with stock sidepipes. Any help would be great. Also, if there were anything else you would recommend please pass it along. I will be posting pictures as the project moves forward.

I’m down to the engine now and my budget is running over. Everything from the Radiator to the Bell housing is brand new 1966 L72 parts. Can you say oh my aching wallet.
:cry

67HEAVEN

As you know, the factory L-72 ran 11.0:1 compression and solid lifters (yes you can hear them). Are you going this route?

I don't agree that the mismatch of head and intake ports won't be a serious problem. I see flow problems.

If your intention is to have a look-alike L-72, you should know that L-72s weren't available with A/C.

Mr D.

Yes I understand and know all the L72 details. While this will ne a NON Numbers Daily Driver, who cares as long as I like it. Living in Fl A/C is a must. As for the 11:1 comp noy looking to go that high and would like to stay with Hyd cam. thanks

396 RAT

Not sure I understand your question.
Sounds to me like your building an L36?
2 bolt, hyd cam, w low comp slugs.
Nothing wrong with that, but I dont get the L72 part?

Mr D.

Ok, maybe I should drop the L72 part. From a external standpoint it will look like a L72. This is due to the fact I already have the intake and other parts. While I know I can go the 390 hp route for internal parts. I was lookinf for a little more hp without reaching all the way to Mech cam and 11;1 comp that was correct for the L72. My goal when this is complete is to have from a external apperance an L72 w/ AC (yes I know that is not correct) and Internal have 400-450 hp using above parts with Hyd cam. Hope this clears things up

67HEAVEN

1966L72,

Having a L-78, L-72, L-71, L-71/L-89 or L-88 mid year is relatively rare, so you'll understand the :confused: reaction from those of us who have them.

As you know, there are a number of major differences between these and a 2-bolt hydraulic engine.....not the least of which is radical idle, solid-lifter sound, high compression sound......and I shouldn't forget to mention the way they rev and pull.

If your intention is to go for looks only, I'd be thinking about eMailing one of the mods to suggest a name change.

Don't get me wrong........I'm certainly not hooked on numbers-matching.....just accuracy in labelling.
:cheers:

Welcome to the forum.

Denney

Mr. D, I tend to agree that while you ~can~ bolt a rectangular port intake to an oval port head, the flow does get somewhat disturbed (unless you are porting the heads to match the intake, and I think that would be a LOT of porting) and it may actually hinder your search for more hp. Since the L36 was already 390hp, it doesn't seem like much of a stretch to push it to 400-425 hp, as you want, doing the normal balance/blueprint/porting of the stock stuff. By the way, my 66BB is also a NOM L72 (it's a 454HO to be precise).

396 RAT

"Everything from the Radiator to the Bell housing is brand new 1966 L72 parts."
Thats what threw me.

"While I know I can go the 390 hp route for internal parts"

Sounds like you want to build a hot rodded L36 based on your components.
I would go 9-1/2 - 10-1 comp.
A quality perf. HYD cam, (lots of 'em out there). (Dont buy an R.V. cam)
Roads lifters for that " Solid lifter sound"
An electronic ignition, (I like the Malory unilite) unless
you have a K66, Headers, Some porting, and have the entire
rotating assembly ballanced. You will have well over 400hp.
Hope this helps.

Mr D.

Dear Hooked on numbers
Yes I will change my name so as not to be confused as having a Mid Year Vette that does not fit into your “Elite Vette Club”. Would not want to upset anyone by putting a 427 cu in in my 300 hp base car that has a 350 in it now. But, on the other hand if money was no object I could just swap everything out and make this a numbers matching L72 car and pass it off as original like most people do.
Please disregard the above questions, as I will look elsewhere for the friendly information I was looking for. To clear up one more item, I do know from talking with people that a BB Chevy engine can produce 400-450 hp on oval heads and Hyd cam. Just looking for what parts and machine work make that possible. (Good machine shop and money will get me the answers next week)

Mr D

Mr D.

Thanks Denney and 396 Rat. I should have said all new parts were external parts. Rad, shroud, brackets, side exhaust, manifolds etc etc.

396 RAT

Talk about starting off on the wrong foot! :blueangel:
This is a great place to talk early vette's.
But in all honesty, your initial question was stupid.
You should have said, I am building a 2 bolt, hyd 427
and would like to end up with 425-450 hp.
Its not all that hard, and folks would be jumping out of the wood work
to help you. And 99.9% of BB Mid yr owners started out with a
small block car, and went from there. You have to understand
there are so many fakes out there someone who has put the time and money
into an orig. deserves a tiny bit of something.
Dont give up on this board, it is the best place for this type of info.
:cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers:

Mr D.

Ok everyone
Sorry about the VERY STUPID question in my Org Post. Let me start over.

Hi my name is Mr D, I have a 1969 427 engine with Oval Port heads and a Square Port intake. I would like to rebuild this and get somewhere around 400-450 hp and still be able to run it on pump gas. My budget is $2000 and I plan to run Cast Manifolds w/ sidepipes and a 3310 Dual Feed Carb. Any thoughts on this?

Mr D

396 RAT

I wonder if an after market dual plane intake wouldnt make more sence?
Many here are using Edlebrock intakes on their BB's.
(I have only used them on small blocks)
Thoughts?
And what type of dist. are you going to use?
Have had some of the best results " bang for the buck" with a
stock single point using a curve kit set up on a dist machine,
or Malory unilite.
And I believe Headers can give most BB's 30-50 easy hp.
Sounds like a great project, sorry for the rough start.
Cam selection is tough. The last HYD BB I had built was a 428 CJ.
Went with a Crane 3500-5500 RPM range cam. But I think they have come a long way since then. Comp. Cams seems to be selling lots of cams these days.
With a $2000 budget you may wish to skip the high dollar valve train and concentrate on intake, ignition, exhaust and ballancing.
Again sorry for the tough start.
Welcome to the Forum!.:jester
:cheers: :cheers: :cheers: :cheers: :cheers:
P.S. 67 HEAVEN is not " Numbers guy" It takes a while to get to know everyone. He is more of a Hot Rodder / Racer type truth be told.
I am more of an **** retentive numbers guy than he is these days.
People do change......... Never thought I would care. :lol:
And yet, here I am. $250.00 for a NOS fuel filter. (still smarts a little)
so be gentle.


[Modified by 396 RAT, 9:50 PM 5/3/2002]

pittsaj

Please don't feel bad....
I can tell you for sure...

I have asked many stuipd questions...
I will ask more... Trust me..

The funny thing is..
All the stupid questions I didn't ask but thought about asking :lol:

One thing I have always liked about this forum is that you can ask them..

We get over them after a good round or two :boxing

One question you might want to avoid is..
Pilot shaft bearings :lol: :lol:

Welcome
Tony

Mr D.

Thanks, I will be using the stock Dist. Before I swap out Intakes I would look into buying a set of square port heads. While the block is a 2 bolt I don't think my driving style would blow the bottom end. Other then a few hard street runs (as hard as one can get away with around town) this will be driven in the 55 to 70 mph range few times a month. If my budget was unlimited I would just go out to Ebay and get me one of those 1966 4 bolt main corvette engines that always seem to be for sale. Gee I would only need to take out a second on the house and sale the water toys.

396 RAT

You can build way more HP than you are talking with a 2 bolt block.
The question is where to get the xtra HP you want?
And new heads plus a rebuild will put you over the 2k you mentioned earlier.
Just trying to help. I still think you can get 450hp out of your engine by ballancing using 9 1/2 to 10 to1 pistons, modern HYD perf cam, free flowing exhaust, matched induction system and upgraded ignition. But then your intake and exhaust manifolds would not look like an L72. Even that might run you past 2k. The extra HP you are talking about does not come in until your in the upper RPM range. You might be surprised with what you have now?
And how fast it can add up when building an engine. I sank about $4000 into
the 428CJ I mentioned earlier. It put out 450+.

ghostrider20

Welcome-
Hey, it's your car, do what you want to it and call it what ever floats your boat.
99% of the public does not know the differance anyway, but the real vetters will, and there is no fooling them. 67heaven should be happy about this. When talking with folks about your car, you can tell them that there is a guy on corvette forum from Canada that has an original and quite rare they are.
And if iterested they can visit his web site and learn more about the history of these cars.

I will agree with 396Rat, I would consider spending the money on matching the induction package. This may sound one sided and how true is to be discovered. A well respected machine shop I have used and the old fellow that owns and operates it say all your power starts with induction ie: heads, intake, cam. The rest is built around that. An example, headers don't do much for a stock passenger car 350 with a 2 barrel and very mild cam.
But it could mean the differance of a 390HP or a 400HP motor.
So I am not sure that running non matching ports is the best route.

I use the PROTRONICS ignitor ignition module inplace of the points, I love them. Points properly set up can be just as good, I just have not gotten around to tricking out points yet.

Can you even buy a factory GM cam for the High performance midyear big blocks anymore?

Mark

Mr D.

I did talk to the machine shop awhile back about this project. They were recommended by a friend who had his 68 BB rebuilt there with good results. The owner told me he would rebuild and rework the head and balance the engine for $2500.00 then run it on the Dyno. His guess was 450HP. We however did not talk about what type of heads I would provide. I guess it time to look at buying a set of heads. I had planned on rebuilding this engine myself to save a few $$$ but looks like I just need to drop it off and pony up the cash at the end. As the saying goes "If you throw enough money at it, the problem will go away" And while we are on the subject of Cam's , am I being to **** about wanting to stay with a Hdy cam??? What are the Pro and Con of Mech vs Hyd. Thanks everyone

Mr D.

Goastrider, where can I get more info the the

PROTRONICS ignitor ignition module

I would also like to thank everyone (even 67Heaven) :jester for this eye opening discussion on my project. I have been hawking this forum for several months now and do know that it is the #1 place to talk Corvette's. Sorry I got off on the wrong foot. Beers are on me. :cheers:

Denney

Mr. D, you are definitely not wrong in staying with hydraulic lifters, in fact, most people I know who ~had~ solid lifter cams put in hydraulic lifters when they rebuilt the engine. Who in the heck wants to adjust the valve train after only a few blasts at WOT?? (I suppose only those who like removing the valve covers :jester ). As far as the lower end, even the 2-bolt main you have will hold up plenty well for a long time based on your description of planned driving. Not to mention that the tires you can put on your C-2 will extremely limit the stress on the entire drivetrain (you can look forward to entering, and winning, many burnout contests if you want.) I don't think you will have that many problems getting the hp you want out of your choice, even for $2k. :yesnod: Of course, you will find, like all of us, that we have this strange habit of blowing our set budgets because we get caught up in the "might as well" mentality during the build-up. Please keep us posted on the progress, I love all BB C-2's whether they are original or not!