what compression are you running with your aluminum heads?
..what are your cam specs and maximum timing?

my Indy -1 heads are 12.6:1 cam is 279/284@50 @ 38* total timing
my Stage 6 heads are 10.6:1 cam is 272/279@50 @ 35* total timing

Indy -1 345cc 14:1 cam is 267/274 @ .050" with 1.7 rockers

Old 451 - B1-B/S Head 11:1 compression (no quench, entire piston dished) 251/251@0.050 Solid Roller, 33* total timing. OK on pump gas, usually ran 50% pump/50% 110 race gas when I raced it just to be safe.

These next two have about 0.040" quench

New 499 - Victor MW Head, 12.4:1 compression, 272 (or 274, I forgot)@ 0.050 Solid Roller, 34-36 Total timing (still tuning.) Ran OK on pump gas for a very limited time, and did not try WOT on pump, usualy ran on 110 race gas or mix of race and pump. Switched to E-85 last year and still tuning it.

505 - Stealth heads. A bit over 10:1 (I think 10.3:1?), 236/242@ 0.050 hydraulic Roller. EFI so timing varies with load and I'm still tuning this. Pump gas only, but it has pinged before (don't know the exact timing because I was using the Edelbrock XT hand-held EFI controller and changing the global timing.

496. Ed heads. .038" quench. 10.2:1 CR. It has a MM lobe mechanical FT 243@.050", .55" lift and 108 deg CL. The cooling system keeps water temp right on the 180 degree stat when rolling.

It is EFI. Maximum "mechanical" timing is 35 degrees. It runs a curve and up to 50 degrees timing under light load cruise with a manual OD transmission. It has pinged at lower RPM when I was experimenting with (pushing) the advance curve and cruise vacuum advance. Back off a little and it is good.

On recent freshen after two hard long track days no signs of heavy load detonation so it seems to like the 35 degrees at WOT.

12.1.1 comp home ported rpm`s(no flow #`s)Isky solid roller .680-.660 276-281 @ .050 timing locked at 35..............470 BB stroker Street car...........

Street or Race ?
Lots of Race responses, so I'll give a "Street"
We just put 10.8:1 static on some Ported Stealths, used an XS282S Comp Solid Flat Tappet with 1.6 Rockers... good for 587 hp/ 592 Trq on the SF902 with 91 Octane, 33* BTDC

Thats some serious power, how ported were these Stealths?

We Ported a very Fat curve on our SuperFlow SF750 Bench, but just under 300cfm @ .600".
I can post the Flow Sheet if you like ? but off my head I think 285cfm by .500", 291cfm @ .550" and 297cfm @ .600".
About 10-12 Hours Port & prep.
NOT cost effective to spend any more on what is really an "entry level" Cylinder Head ?

Was that a stock stroke 440?

10.9 compression, timing locked at 35*. 394 ci small block runs on 93 octane. 255/266 @.050

400 Block based "451", but yes stock 3.75" (440)Stroke.

Mine street as it runs good on 92 pump. 440/493 stroker with 4.15 crank. Basic EZ heads with mild porting and 10.6 comp with the D-dish pistons and .045 quench. Solid flat tappet 264 & 270 @ .050 with .585 & .592 lift on a 110 LSA in eng at a 106 ICL. 36 total timing and no ping at all on 92 pump. Ron

Thats a strong running engine, darn impressive for a somewhat mild cam

572", Indy -1 , 58 cc, 15-1, flat top w/10cc notches, .005" deck height, 285/292@112, LCA, 32 degrees, Renegade 114 or 116 fuel, no quicker with more timing.
Doug

Currently running 11.5:1 on 91 octane. Timing is around 10 degrees? i think... i never really have to mess with it. Good head design FTW!

I run Stealths with 12.5 domes on the street.Cam is Comp .588 lift and IIRC around 320 duration.Run 34 timing on my MSD.It will clatter under heavy load with 93.If I dont really get into it I can drive foreve on 93.Mix in some 110 race fuel and its good all around.Rocky

Street combo

360 zero deck slugs, ported, lightly milled rpm heads for a 11-1 ratio
Small solid roller, 250*@.050/.600 lift
In at 34*

Ported Stealths, 10.5:1 CR, 91 pump gas. 235/241 duration at .050, .545 lift hydraulic roller. Never a hint of detonation.

was 10.2:1 on Indy-1 255 cnc raised port heads and 408 cubes
New will be 11.5:1 with same heads and 410 cubes, still rocking that 93 pump gas