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!