So i'm getting closer to having my 383 setup done and I would like to get a few opinions on it so far and on a couple other things..

I'm looking for 7.5-7.8's in the 1/8th mile on motor, would the following setup be enough to push the full weight Z to those times?

Setup so far:
383ci LT1
Mahle Forged Pistons
Compstar H-Beam Forged rods
Compstar Forged crank
Ported Heads(Flow #'s: .50 I-253.3 E-165.8//.55 I-261.0 E-171.2//.60 I-262.6 E-175.8//.65 I-261.8 E-180.1)
Ported Intake w/ 52mm TB
CC503 w/ Crane Gold 1.6RR, and Comp Beehives
LTCC
Pacesetter Coated LT Headers and ORY
Borla Exhaust
LT1 Edit
PA Racing Chromoly Tubular K-member
BMR Xbrace and Random Tech TQ arm
UMI SFC, Panhard rod, LCA and relocation brackets
Wolfe Racecraft Rear Swaybar
Hal QA1 12-way Adjustable Shocks, Front & Rear
300# front springs/ eibach pro-kit rear springs
Moser 12 Bolt w/ spool and 4.10's
Built 4L60
Prostars 3.5"/8"

I plan on upgrading the cam and heads in the future. How do my heads compare to stock?

Thanks for everyones help in advance..

 

Are you trying to be emissions conscious? If not I think you are undercamming that engine. You'd be much better off w/ a CC306 or GM847 or equiv. If you are trying to stay e-check compliant then there may be a larger cam you can run and still pass a sniffer. I don't know off hand. Maybe someone could chime in.
Even with that cam as long as you are set up to launch with the correct gearing you should easly be in the mid to high 7's. I was able to muster a 7.76 @ 90 w/ my stock block LPE heads/211/219 cam.

 

I'm the first to tout the benefits of smaller duration cams, but I'd like to see a bit more lift than the 503 provides (even with 1.6s). I run a 226/234 .568" in my 383 and with a Vig 3600 and 4.10s it ran the numbers in my sig...My heads appear to flow similar to yours..They were originally done at LPE with 2.00/1.56s and then re-ported by Eric Bradby 2 years ago and the flow numbers are similar...I also ran the LPE 211/219 in my 383 for a number of year and it ran high 11s/low 12s at 115...Look at 22X/23X duration with no more than .570" lift and you'll be thrilled...When matched with 4.10s and a 28" tire you'll cross at 6500 which is very nice for longevity and street fun...I have since upped the Vig to 4000 as it better matches my torque peak on the dyno...We'll see if that works next season...FWIW I run the 1/8th in 7.14 @ 96...

--Alan

 

Why would you limit lift to .570" max.?

 

I was told a long time ago by Joe O. and John Lingenfelter that in the majority of cases when using LT1 heads even ported with the bigger valves, that any lift over .570 is wasted because the heads don't support it...I'm assuming that they knew/know what they are talking about...

--Alan

 

My heads keep gaining flow until .650 lift. 281.6 @ .550, 283.7 @.600, and 284.9 @ .650, so more lift in my case would = more power which is supported by the fact that my cam has over .570 lift.

 

Mine did too, I'm just following the advice given to my by some folks who know way more about what works and what doesn't with these motors...and what I've seen in real world results...I said in my earlier post that in the majority of cases .570" is about as high as will be effectively supported...I'm also talking about street/strip set ups which is what I though the OP was building, and what John Lingenfelter was all about...

I was offering advice that apparently works and if folks don't agree with it that's cool with me...I just continue to see lots mistakes being made which can make this fun hobby not so fun...At over 121 mph I'd say thanks to John and Joe for good advice and keep on keepin' on..Until I see the bigger street stuff running faster than 120 mph I'll keep doing what I do...Not at all trying to be an ***, just stating what I've seen that works well...I know that every set up is different and no two cars are the same...I was just giving some (what I believe is) good, general info...

--Alan

 

I agree on getting advice on people who have experience and proven track results with lt1's. I'm sure thats why you went who you did for your h/c setup and thats the same exact reason i with who I went with for my new h/c setup. With any luck I'll have some track times in 1-2 months with my new setup, until then I'm not going to speculate on what I'm going to run but I'm hoping that I'll be impressed. And your car is running some damn impressive times too, faster than some solid roller cars on this site.

 

Ya I figured the 503 was a bit small, but the only reason I got it was because I got it for $100 so... That was the reason on that..

Lets say I sold the 503, what cams would you reccomend? Are the XE grinds any good?

*edit*

Also, is there an up side to have the same lift for both intake and exhaust over the lift being higher on the exhaust side then the intake side?

 

The XE lobes are notoriously hard to get to rev. The rest of the valvetrain has to be set up perfectly for them to work correctly. Don't use the HR XE lobes unless you have the time/inclination to experiment or use the services of an expert to setup your valvetrain. OTOH, they do work great for many street, street/strip blower setups which do not need a lot of revs. That out of the way, I am not a big believer in may of Comps off the shelf grinds. Many of them seem to have too wide an LSA. The 503 is one of my least favorite.

Rich

 

So I called Brett and talked with him, told him my setup and ended up with a cam from him. Its a 23x/24x .57x/.57x but he said he had them "grind it smaller, so its a tad bit smaller then that..". I take it that means it has a little less lift?

I also went with a vented opti conversion, and a progear timing chain.

I'm now looking at tires and TB's.. I want MT DR but now sure what size would be good w/ the cam and gears. Any reccomendations? Also I have a stock TB, I figure I need atleast a 52mm maybe more for growing room... Should I have the stock one ported or buy an aftermarket one?

Sorry for all the questions, I'm still new to all of this.

 

Are ya thinking XFI lobes maybe?

I think the cc503 is a great performer in the correct application. To me that would be a stock displacement / stock head car. I also don't think the cc503 is designed to be a revver anyways... I only needed to spin it to 6200 for my results with it.

I went 12.0 @ 112.81 through stock heads, full exhaust, and a 3200 stall with the cc503. Had another friend that duplicated my build locally and he went just about the same times.

I agree this build above is not the correct application for a 503.

 

I have an LPE/Accel 58mm and love it...Without having the car dyno tuned to see where the hp and torque curves fall its a bit hard to spec gears and tires, but I'd look at a Vig 4000 converter, 4.10s and 275 60 R15 M/T radials...Thats the set up I have now and go thru the traps at 64-6500 rpm..Your cam is a wee bit bigger, but 4.10s with the 28" tire should be a good start...Generally converter stall speed should fall between 500-900 rpm below the torque peak...I ran a Vig 3600 for years and ran the times in my sig with it, but just had it restalled to 4000 based on where my motor makes peak torque...and I'm actually still on the low side of stall, but I don't want to lose drivability...

--Alan

 

I through a convertor in that mix also...36-3800 stall would suit you pretty well, Id think.

If your gonna upgrade the TB, just go all the way and get a 58mm. All you'd have to do is port your intake for it, thats pretty cheap.

 

I have the summit racing brand 58mm throttle body and it works great for me. Only problem I ever had with it was I had split fuel trims with it so I had to modify it to help out with those. But I do think that is with about any aftermarket throttle body.