Heres the combo:

355 Dart S/R Heads(Same as World just back when Dart made em-they have 1.94/1.5 valves-untouched)
Comp Pure Energy Cam 203/212@.050 .425/.439
9.4 SCR
Holley 650 DP
1.5 Roller Rockers
Dart Sporstman Dual Plane(same as RPM I have been told)
MSD Pro Billet, Blaster 2, 6A Ignition box
1 5/8 Headers through 2 1/2 Flowtech Afterbuner mufflers dumped at rearend.

In a 3800lb 81' Camaro with a Tremec 5-speed and 3.42s the best I've gone is 14.3 @96.5mph with a spinning 2.1 60ft time(still haven't gotten the hang of the Drag Radials yet).

This is what I am planning to do this winter:

Take off the heads and midly port them(smooth bowls, remove castings, slim valve guide bosses) and then install either a XE262(218@224@.050) hydraulic cam or the similiar XS262 grind that is a solid cam(224/230@.050 .460/4.67 or something).

Assuming I know what I am doing and don't mess up the heads, how much horsepower increase and ET decrease would I see? I'm kinda on a budget here but next year I really want a low 13 second pass. Thanks guys.

Chris may or may not be around this weekend so I'll post this to give you an idea of what a combo similar to yours might run:

Chris Avery aka username=fuji
'69 Nova, 355, 9.3:1, Keith Black 12 cc D-cup hypereutectic pistons, 180 cc Dart Iron Eagles w/64 cc chambers, Comp XE-262, Crane Energizer 1.6 ratio roller rockers, Performer RPM, Holley 650 DP, TH350 w/B&M shift kit, B&M 2400 RPM Torkmaster converter, 4.10 10-bolt posi. Best 1/4: 13.098@103.41, 1.949 60'

P.S.- He ran 13.45 @ 104 mph with 3.08 gears. The optimum gear ratio for that cam seems to be 3.4(?) - 3.5(?) or so, notice he lost mph going to 4.11's. Sleeper combo for sure. ;) Hope that helps.

[ 09-06-2003, 01:18 PM: Message edited by: rmcamaro ]

I looked real close at a set of the newer World SR castings and their was a lot of room for improvement in the bowls right under the seats. IMO doing a decent home port would be worth 25HP. More extensive porting could find even more.

As for the cam, I think you would pick up another 20-25 with the Comp XS grind, maybe a little less with the smaller hydraulic cam.

Both IMO are good ideas and should help you pick up some power for next year graemlins/thumbsup.gif

Eric,
I'm just asking because I don't know. I've heard the the SR designation on the heads stands for standard replacement. Is that true?

S/R's are stock replacements, and the s/r torkers are stock replacements with bigger valves. They have slightly bigger ports than stockers at around 170cc...perfect for a street/torque head. I agree with Eric...mild port work on the heads and the xe262 cam (or similar) will add around 50hp.

You should get a mid to low 13 second pass with what you are planning to do.

The Sportsman intake is not the same as a Performer RPM.It is somewhat close though.The Sportsman has a slightly deeper plenum and it also has that small area cut out of the plenum devider.I have both of them, I also have a Holley 300-36.I am planning to do a comparison of them sooner or later.

I had a 650DP on a Performer RPM and it didn't seem to run right till I put on a 1 inch open carb spacer.Maby the small cut out on the Sportsman intake will make it a better piece for the small carb (without a spacer) since it creates less suction on the carb.

The engine was a 350 with 10:1, an early set of Dart/World S/R's-202/160 valves, with mild bowl porting, Crane HYD cam 222 278 467 110, MSD 6 ignition, 1 3/4 headers, 2600 stall, TH-350 trans, 3.42 gears, and 26-8.5 slicks.All of it was in a 79 El Camino that was about 3600 pounds with me in it.My best pass was a 13.01 at 104 with a trans that was slipping when I shifted from first to second.

Something I found on my early S/R's is that the port entrance was slightly smaller than the port exit on the Performer RPM.This means that some of the air and fuel mixture was crashing into an obstruction, disturbing the mixture before it got to the combustion chamber.This had to be hurting the power somewhat.
If you are going to be removing your heads make sure this is not the case with your heads.You want the heads port entrance to be either the same size or prefurably slightly larger that the intake ports exit.

Toby,
Yup, S/R stands for stock replacement.They have the same intake port as the early 461x fueler castings wich had 170cc intake ports.The exhaust port is slightly different but very close, at least that's what I was told by my head porter.The combustion chamber is shaped like the fueler also.The chamber is slightly larger around the intake valve to promote air flow a bit.
That's on of the problems with converting a 194 fueler head to 202 valves.The air flow is hamperd by the close walls of the combustion chamber so you didn't realy get the full benifit till it was slightly relieved.

Thanks guys.

Mutant, how much did your car weigh with that combo and what was your 60ft time? Anything special that I should look for when porting my heads?

Weight was about 3600.I can't remember the 60 foot time as it was about three years ago.The cars been apart since then.

I don't know of anything to watch for as I gave my heads to a known head ported for the pocket porting.

The only thing I know of to watch for is the intake port opening like I mentioned.The porter who did my heads didn't believe me about it so I drove out to his place with a Fel-Pro 1205 gasket wich closely fit the Performer RPM intake.I laid it across the intake and then across the heads.He then bit his tongue and agreed.He also offerd to gasket match the heads to the 1205.
He was slow at porting the heads and my car was already down for two weeks.With no other means of transportation I opted to just run them.When I look back I should have gave him the heads for the matching.Then that 13.01 would have never reared it's ugly head.

About the XE cam line.Yes it's true they will make more power but there is something to remember when choosing that line.
They are agressive.Wich means they will give you more power, at a price.They are harder on the valvetrain and will wear out quicker.It is something that is being brought up more and more here and on other boards.If long term usage is your goal use the Magnum line of HYD or SLD cams.
You will still meat your goals with proper tuneing

[ 09-07-2003, 05:36 PM: Message edited by: mutant 68 ]

Mutant68,

Hope you get the comparison tests done so we can all learn a little more!

My -461 big valve heads have the classic hi-po combustion "bathtub" shaped chamber whereas the medium valved and maybe the small valved -461 heads may have the "squared-off" combustion chamber.

I mention this b/c I bought a set of W/P's SR Torquer big valved heads and they are the "squared-off" chambered type!

AllGoNoShow,

BTW, I bet that Dart Dual Plane is a GOOD manifold, imho....

And DON'T sell the good old CC 268HE or the Crane 272/272 Energizer cam short!! They both will make great midrange torque AND last a long time like a stock cam...

pdq67

pdq,
I believe you are right about the combustion chambers.The 461x casting had very small combustion chambers, somewhere around the 57cc mark.I think the S/R's chambers are about the same as the later 186 Fueler castings wich run about 67cc.Something I neglected to mention.I could be wrong here cause I got rid of my 186's about two years ago and can't compare them.

[ 09-07-2003, 10:30 PM: Message edited by: mutant 68 ]