I have a 72 Charger street/strip car, but I mostly use it for bracket racing. Mostly on 1/8 mile because of distance to track.

I have built it from swap meet finds and left over parts from other projects.
To keep it fun I want to stay on a budget, but until I have a wheelstander I am willing to spend some more

I'm considering a pair of Sidewinder heads and it would be interesting to hear from you experienced fellows:
1. how much faster would they make it?
2. if they are good as they come OOTB?
3. suggested compression ratio, gaskets and springs?

I don't know weight but it has fiberglass fenders and both bumpers including brackets, plastic grille, no back seat and lightweight bucket racing seats. No heater box or carpet.
Welded in subframe connectors, Comp Eng Slide-A-Link bars, 318 torsion bars, 90/10 front and race shocks in rear. Cold air T/A style scoop.

Block is a 440 bored .030, top decked, fully balanced steel crank with
JE custom flat top pistons flush with cyl deck,
Hughes solid cam HTL5256BS (610/614 w/1.6 rockers, 252/256deg, 108 deg lobe sep angle).
906 unported, just cleaned up and matched to intake, and milled down A LOT. With 200 psi Kevin on Hughes estimated my comp ratio to around 12.6:1... Race gas is no fun!
Harland Sharp 1.6 rockers,
M1 intake,
950 Holley DP,
tti 2" O.D. tubes with 3-1/2" collectors extended around 18",
I have modified an universal crank trigger ignition with dual coils, fully adjustable. 10 deg at start and a flat curve running, seems like it likes 36 deg best. Big difference compared to the MSD I ditched. No splutter, no missing, fires right up and steady readings.
Man valve Th 727 w/ unknown 10" converter,
4.30 sure grip
Best 1/8 run 7.32/95.3 mph, 1.662 60' on 9" slicks, slippery track.

Thankful for any input folks!

Those heads must have been milled a lot. Like .100" to get that kind of CR, if that's accurate.

IMO you are really cranking for unported 906s. Compression helps. But more headflow should really add power with everything else you've got going on, the heads are the weak point for sure. Stock valves or 2.14/1.81s?

Also, assuming you've got something like 6 cc valve notches I think 12.6:1 compression is a high estimate. You'd need a 65 CC combustion chamber which on a 906 would be milled until the step pad was gone, although people have done that.

You do the math: unported 906s flow max of 228cfm. Sidewinders are at least 270. 1cfm can make 2hp. 40# weight loss to boot.
Todd Marsh is supposed to be selling them ready to go.

But since the Sidewinders came out Trick Flow has dropped a new head into the market and that flows maybe 330 out of the box. I can't remember, but there are a lot of posts here about both sets of heads.

R.

Curious: What altitude is that track??

Generally speaking at 0 deck flat top piston with a 79.5 cc chamber is right at 11:1, depending on head gasket. That said, to be a 12.6 with milled 906's...is a very generous GUESS-timate.

2" headers seems a little extreme to me but im no expert

What is your goal? Do you want to spend some $$, and about how much? I would go with heads first, if it is in budget. Keep the compression up there though, or it will cost you a lot of what the heads gain. You can run the lash tighter, which may provide a decent return on investment! Try the intakes first. (.016?)
On the heads, the sidewinders by trick flow may offer some advantages over the other aluminum heads. Keep an eye out for some results , hopefully accurate back to back tests against other aluminum heads.
Finally, fine tuning everything in the car may pay some dividends as well. Leave no stone unturned, if you haven't already. Guys here love to help,,,,,

A rough guess is that around .100 has been milled off, the step pad is almost gone.
The valves are 2.14/1.81s.

I talked with Hughes after getting 200psi cylinder pressure and this is the answer:

I went ahead and did some calculations.

Based on the altitudes listed below (choose yours) here is what I estimate your compression ratio to be.

At sea level to 500ft above you would be approx. 12.5:1
750 to 1500 ft above sea level you would be approx. 13:1
2000 to 3000 ft above sea level you would be approx. 13.6:1
3500 to 4500 ft above sea level you would be approx. 14:1

Good luck,
Kevin

My elevation is 600 ft.
Cam is installed (and dialed in) centerline at zero, after Hughes instructions.

It might be a high estimate, but I know it's too high for pump gas.

I should have cc'd the heads and cylinders when it was out, but I had no time, the race was next morning. Anyway, that is not an issue, I want aluminum heads and I want most bang for the buck. Also, next time I will measure

Well, my goal is most bang for the bucks. I can spend a grand that Sidewinders cost, and maybe even two if the Trick Flow's are worth it. But I don't want have to buy new rockers or something else expensive.

With alu heads I guess I will be relatively safe with something like 11:1 on good gas?

Talking about lash I had to do some investigation, I don't have the papers that cam here right now. When I googled I found that Hughes specs .010/.012 for my cam, they call it "tight lash design cam series". I have to look in my papers, but I think they had a bigger number there. Thanks for the tip!

You might be correct, but I traded them for an old rusty pair of 1-3/4" Hooker Super Comp's

Track altitude is 700ft, my shop where I measured cyl pressure is 600ft.

Have no opinion on comp ratio, just referring to Hughes etimation...

I have not used a Moroso stick.
Someone dares to guess how much hp/tq my engine cranks out?

Buy my car.. it will wheel stand for ya... its
light and if you want you can buy it as a roller
or turn key... with your engine and trans in it,
it would be 2500# with you if your 200#.. then save
your car for the street

If the heads were cut .100", that's close to 20cc on 906's.
If you buy new heads, I would cc the old ones before deciding on exactly what to do with the new ones.
If you're really at 12:1+ now, I would be hesitant to lose much of that if added performance is the goal.
The 60' times are kinda soft for a 12:1 440 with a high TQ cam and 4.30 gears.
I suspect the "unknown" 10" converter may not be getting it done for you.
I've always been a believer in running as much stall as a combo can take( race car, not street car), and I'd be looking at like 4700-5000 with that combo....... But honestly, when I put new heads on I'd probably add about 10deg of duration and then up stall speed to 52-5300.

I admit that a lighter car with a professional chassie would make me faster, but I love my old school car and she can't help she's a b-body
I'm not a professional racer and will never be, my companies, other hobbies and family take too much time. All I want is to be a little faster with a fair amount of $$$ and elbow grease.
I'm pretty sure the heads holds her back, but some input from experienced racers can never be wrong
By the way, how did you know my weight?

I will, if I get new heads, cc them and try to find a good compromise in compression ratio before I bolt them on.

My carb is not fine tuned yet, I had a slight bog right of the starting line. Got the best 60' times when I had her at around 1,500 rpm's and just slowly pushed the pedal at starting line. It still bogs a little when the converter grips. Will have to spend some time to sort it out, but had new heads in my head ( ) already so I didn't care too much.

I have a 3.91 SG lying. Is my car too heavy or could it work with my torque cam?

Here she is

One more

Have you thought about doing some porting work on your own? If you ask on here, info on what to do for starters to get about 50 to 75 percent of possible flow gains can be done by the average guy taking his time. You could start by working with the valves you have, or upgrading the intakes to 2.14 size. Just doing the intakes will keep the cost down, and I am betting on good gains, even leaving the exhausts stock. Some of the other posters here can maybe chime in on that last suggestion.