Hi all,

Im doing a restoration on a '65 300 and heres what Ive got cookin under the hood so far. The car came with a 194 6 banger and powerslide tranny. Ive gathered up a '73 L82 350 and a turbo 350 trans to rebuild and install.

The motor was recently rebuilt, punched .030 over and is still real tight so Im just doing a re-ring job on it. I plan on replacing the smog heads with a set of 194 camelhumps, I figure this will put me to about 10-10.5:1 compression. Im going to port the heads myself. Ive got a holley 600, an older eldlbrock performer (came with the motor) and a gear drive timing set, oh and an HEI distributor.

I havent decided on a cam yet, Im looking for good bottom end torque and fairly easy (mpg) highway crusing.

Any suggestions for simple (affordable) things to help achive those things? Cam reccomendations? What am I overlooking?

Oh, Im farmiliar with port matching from working on diesels, but what is "pocket porting"? Is it a cnc thang?? :confused:

First off, have you considered a set of Vortec heads? They perform very well for the price. The down side to them is that you have to have a Vortec specific intake manifold, valve covers, and self aligning rocker arms. I had a 355 with these heads, an xe268h (224 230 @.050 .477 .480 lift) hydraulic flat tappet cam and that motor performed very well. I figure it was around 375 hp at 10:1 compression. If I were to do it again, I would use 1.6 rockers. If you are set on the camel humps, a ported set of those will perform about as well as an out of box set of Vortecs, so either way should work well. The performer intake is ok, but I think you would be happier with a performer RPM. Below is my complete setup. With a 700R4 1900 stall and a 3.90 gear, the car got 18 mpg on the interstate.

1972 ventura
355
10:1
vortec heads
650 holley dp
xe268h cam
performer rpm intake
1 5/8" headers
GMPP hei

With your setup, I would recommend the same cam with a 2200-2500 stall and a 3.55 gear. With a 28" (275/60/15) tire, that should put you right around 70mph at 3000 RPM.

As for the porting, someone else can probably do a better job than I when it comes to the details of pocket porting. As for CNC, it stands for computer numeric control. In essence, a machine ports the heads. Someone can write a program for an optimal port job and then the machine can punch out as many of that port job as you want.

Adam

I'd think of a set of World Products S/R Torker 67cc heads from Summit or Jegs. For $250a piece bare, they are a bargain. And Summit will ship both for $11.99!! I have them on a 307 and it runs as good as any small block I've ever had for the street. They do come in a larger cc size as well, and choice of 202's or 194's.

I'd think of a set of World Products S/R Torker 67cc heads from Summit or Jegs. For $250a piece bare, they are a bargain. And Summit will ship both for $11.99!! I have them on a 307 and it runs as good as any small block I've ever had for the street. They do come in a larger cc size as well, and choice of 202's or 194's.


The World/Dart line of stock replacement heads are really good heads. I've ran 165 Darts and they are a truely good gain for the cash. Why spend the money on some 25+ year old castings and spend $500 or more for them to get refurbished. Spend another $150 and get a NEW casting with NEW parts ready to bolt on and go!

A cam for what you want is easy to pick. a cam with less than .230 druation and a 112-114 LSA is what you want. Plenty of manners and nice lope at the light. I'd recommend a Summit .214/.224 @.050 duration cam.

Hi all,

Im doing a restoration on a '65 300 and heres what Ive got cookin under the hood so far. The car came with a 194 6 banger and powerslide tranny. Ive gathered up a '73 L82 350 and a turbo 350 trans to rebuild and install.

The motor was recently rebuilt, punched .030 over and is still real tight so Im just doing a re-ring job on it. I plan on replacing the smog heads with a set of 194 camelhumps, I figure this will put me to about 10-10.5:1 compression. Im going to port the heads myself. Ive got a holley 600, an older eldlbrock performer (came with the motor) and a gear drive timing set, oh and an HEI distributor.

I havent decided on a cam yet, Im looking for good bottom end torque and fairly easy (mpg) highway crusing.

Any suggestions for simple (affordable) things to help achive those things? Cam reccomendations? What am I overlooking?

Oh, Im farmiliar with port matching from working on diesels, but what is "pocket porting"? Is it a cnc thang?? :confused:


Be careful on the cam and head selection. The doulbe hump heads and a mild cam will spell disaster in the form of too much cranking pressure and detonation.

If you want good mileage and a mild cam stick with the smog heads and a mild pocket port. The Comp Cams XE256 is a great cam for the smog headed motor with the 76cc heads. This combo will make about 300HP and about 400TQ if assembled correctly.

If you are set on running the doulbe humps, the Comp Magnum 270H old school cam is great in this combo as it will bleed cylinder pressure and will have a great lopey idle. I have build both combos and both were nice for what they were designed to do. This combo with the pocket ported double hump heads will make in the neighborhood of 325-350 HP and great TQ depending on the parts combo picked.

Either way, Good Luck! :D

Thanks for the input guys. I got my kit yesterday. The cam I settled on is very similar to the 270h that Chris reccomended. Its a HiTech 102401, 450I 460E 224 durr. 114*.

I really dont know if that is going to bleed off any pressure or not, I hope so.

I know the Vortec heads are awsome, as are many aftermarket heads, but Im kind of a nostalgia nut which is part of the reason for the humper-pumpers. My nephew is working on this with me and he in into building up four bangers and I want to share some old school muscle with him.

Im going to give the fuelies a try and if detonation becomes a problem then I may try something else.

Any speculation as to what kind of idle quality Ill get from that cam??

Again thanks for the input..

Shouldn't your 1973 L-82 come with the larger 2.02/1.60 valves and more HD equipment then most other engines?

Thanks for the input guys. I got my kit yesterday. The cam I settled on is very similar to the 270h that Chris reccomended. Its a HiTech 102401, 450I 460E 224 durr. 114*.

I really dont know if that is going to bleed off any pressure or not, I hope so.

I know the Vortec heads are awsome, as are many aftermarket heads, but Im kind of a nostalgia nut which is part of the reason for the humper-pumpers. My nephew is working on this with me and he in into building up four bangers and I want to share some old school muscle with him.

Im going to give the fuelies a try and if detonation becomes a problem then I may try something else.

Any speculation as to what kind of idle quality Ill get from that cam??

Again thanks for the input..

You bought another L-82 cam! That cam does work well with some compression. The double hump heads will put you right about 10.0-1 compression (depending on head gaskets and deck height of course) with the factory style L-82 pistons (TRW L2417, flat top with single trough type valve relief).

George,

Yea, theyve got 202 heads but they are 76cc low compression chambers. Ive also read that theyre prone to cracking but Ive not torn mine down yet. They also have a few other pluses, the '73s are basically a 300 hp motor (250 hp net) Id like to get to about 350.

Travis,

Im not sure what "single trough" means, but the pistons I have do have valve reliefs, 4 on each one. Ill be using stock composite head gaskets. Nuthin fancy..

Im glad to hear that cam does well with compression. Do you think it will have a lopey idle or smooth??

That cam has a mild lope to it in a 350, and should pull about 15" vac. It will also rev to 6K easily with a mild valvespring (like the $30 Z-28 replacement springs available everywhere). Install it 4* advanced as it has no advance ground in, and 1.6 rockers work very well with it also.

Install it 4* advanced as it has no advance ground in, and 1.6 rockers work very well with it also.


Im not sure what you mean by that, does that mean that when I install the timing set that the marks need to be deliberatley mis-aligned??

Bryan,
The factory way is to align the marks on the crank and cam sprocket. Better builders, all the pros degree the cam.
You'll need a cam degree kit (borrow one and someone with experience in doing this) and a timing set that features several keyway settings. Advancing the position of the cam pumps up the bottom end power, retarding the cam makes a bit more power on top.
Another way to change the degreeing of the cam is to run offset bushings with a timing set that does not feature different positions.

Search "How to degree a camshaft" also available on CD in some of the "How to rebuild your SBC" books

Pocket porting:
After the valves are out of the cylinder head, the area below the valve seat, the pocket, gets blended smoothing the transition between the casting and any machining sharp edges....also removing any casting irregularities.

Stock, true 4-notch flat-top pistons, 64 cc heads ans .020" thick, steel shim headgaskets will create an about 10 to 1 CR.. engine even tho GM spec'd them back then as 10.25 to 1!!

I figure blueprinted, SURE!!

The old .450"/.460" hy-cam will do fine, altho a bit weak at 10 to 1 b/c, imho, it really need's 11 to 1 to run it's best just like the old -151, 350hp/327 hy-cam and the -178 and old 30-30 which are both solid lifter cams!!

pdq67

Well, as far as adding a "special" timing set, Ive got a dual idler set that I will be using. I expect that it would work if I knew how many teeth to turn it.

That's what I figured about the pocket porting. Thanks!

Lots of great input, I appreciate it guys!