Sorry this is long but here we go.
I have been at the track the last few weekends racing Hot Rod/Super Street. Unfortunately, I was eliminated a little earlier than I would have liked on Sunday and was able to made a couple of wide open test hits. I have done quite a bit to my car and I was fully expecting it to pick up. I will describe my previous combo and what has changed and you guys can offer advice.

Original Engine Combo
512 cubic inch 400 based engine
3.380 Bore - 4.250 Stroke
13.5 Compression
Max Wedge ported Indy SR – ported by Jeff at Modern
1.5 Ratio Harland Sharpe Rockers
1050 Chuck Nytten Gas dominator
Indy 4500 Intake with approximately 3/4” of spacer
Hooker Fender well headers (44” Primary Tubes) with 3.5 inch exhaust exciting before the rear tires
Scott Brown Roller Cam – 630 lift with 1.5 rocker, 278 Duration@ 50, 112 centerline

Transmission
Powerglide with 1.80 Straight cut gear set
5600 PTI 8” Converter

Rear End
Mark Williams Sheet metal 9” with aluminum center section and rifle drilled 40 spline axles. 456 Gears

Chassis
1971 Demon all steel except fiberglass hood, deck lid front and rear bumpers
Full cage with round tube back half
Factory Glass
6 pack hood scoop – carb not sealed.
Stock engine compartment with inner fenders except where headers go through
Factory dash
4 Link rear suspension
Custom built rack and pinion Front suspension.
QA 1 Double adjustable Front Shocks
QA 1 Double adjustable Rear Coil Overs
Anti Sway bar
Goodyear 24” front tire
Goodyear 32 x 15.5 x 15
Car weighs 3040 pounds with my big butt in it.

Best ET with this combo is 9.58 @ 139 with a 1.36 60’. That took placing the fall in 2007 and I don’t have a corrected altitude.

1st set of changes I made.

Changed Heads from Ported SR’s to INDY -1’s CNC 325
Replaced the 1.5 Rockers with 1.6 Rockers
Went from Hooker Fenderwell Headers (44” primary) to shorter Headman Hustlers (36” primary) – both 2”
Removed the exhaust
Removed non sealed 6 pack hood scoop and added a sealed pro stock scoop.
Replaced the PTC converter with an A1 that stalled at 6200
Replaced Goodyears with Hoosiers. 26”on front, 32”x15.5” x 15 Slicks

September 2013 – Corrected Altitude - 3409
60’ 1.401
330’ 3.973
660’ 6.145
Mph 113.20
1000 8.029
1/4 9.625
Mph 140.75

2nd Set of Changes

Lowered the Stall to 5600 to try to get the pig to leave
Added a Star Machine Vacuum pump and puke can

June 2014 – Corrected Altitude - 3971
60’ 1.386
330’ 3.958
660’ 6.139
Mph 112.78
1000’ 8.029
1/4 9.636
Mph 140.14

To be honest I thought that it would pick up a bit. In the past removing the exhaust was a tenth. The shorter headers were a 15 – 17 horsepower better on the dyno. I thought the heads would be a wash. I thought that the rockers would help a tiny bit too. Also sealing the scoop to the carb is supposed to be the best thing since nitros.

Any Input would be appreciated and any suggestions. I would really like to get this thing to leave.

Did you try to shift it higher or lower? did you dyno it? What do you shift it at? What does the converter fall back to when you shift it?

http://youtu.be/RTDkU8WCjLo

I say you are leaving a lot on the table with that small of a cam.

Whats the 4 link settings

See im looking at it alittle different. Those old no. were your best. what was your average. did the compression stay they same from the different heads,did you have it back on the dyno and retune your new combo,it may be out to lunch. also Im thinking that is a lot of converter for that thing hardly any mph for that et even thou it picked up 1.5 mph from your old Best!!

1.5 MPH over your previous best is good news so you are making more power. 60 foot is still pretty soft with lots of opportunity for improvement.

If I were the OP, I would give Dwayne Porter a call with all your combination, and have him spec out the correct cam for you.
I would bet good money doing that one thing would show solid gains across the map.

Why is the cam so small. Is that what Scott wanted to put in it, or were there limitations. You have a race car motor, with a street car camshaft

Speaking of Scott, he does a LOT of cams for me and I have had nothing but VERY good results with everything he has ever done.

Monte

Look at the head flow at your current net valve lift(.600) versus what you will have with about .725 lift (.750 lift gross). A decent roller for your combo IMHO would be about 280 to 282 at .050 intake, 288 at .050 exhaust, on a 110 LSA probably in at 108. The 110 LSA is that wide to accommodate the long 288 exhaust duration and keep the overlap about right. Less exhaust duration might dictate a cam of 108 LSA. These numbers are coming from all the recommendations I have gotten for my 528 with 440-1 heads. I am not that much bigger than your motor, so the cams ought to be similar. Also, the smaller the intake valve to cubes, the narrower the LSA needs to be. The reason is the poorer the heads flow for the size motor, the more overlap is needed to get the intake flow moving.
The first cam I had in the 528 was an Isky RR735.
It had 280/288/110 specs, .735 intake lift with 1.5 rockers. I had 1.55 ratio rockers on then for .761 gross lift. That cam made 847 hp on the dyno, and the car went 8.77 at 153 on radial slicks at 3,000 lbs. That would be about 8.85 on bias tires. You have a lot of power there, it just needs to be unlocked with a cam and compression. I run 15/1 with alky, and wouldn't run less than 13.5 or 14/1 with gas.
I am also a fan of very loose converters. They flat work for me. I got a $1500 lesson on that this spring. I tried another converter, set for about 500 rpm over peak torque. The car slowed over 2 tenths!. My current converter flashes to 6600 and I shift at 7100, which I know is very loose, but it is at least .05 faster than it was flashing to 6,000.
You run a glide, so being loose enough would be even more important to you, IMO. I run a three speed.

Thanks guys for the responses. I had a chance to read them but I have been crazy busy so I could not respond till now.

The cam was designed for the 451 I had in the car previously. It worked well in that motor. It was easy on parts and I had not had issues with it. We had dynoed a friends motor that had a way bigger cam in it and the results were similar so I went with it. I must admit I was a little hurt when the dyno operator asked me what year motorhome the engine was going in once he had heard it run.

With regards to the 4 link I think this is the area I need to concentrate on. I have a set of scales and I am going to scale it. I will also plot the bars once that is done and I know where we are at I can make some adjustments. The issue at our track is we don't get any runs so it could take a full season to get the four link set up. I realize that if I want it to work right I need to do it but I also want race.

I am still not sure that the converter is right. I have attached a copy of the dyno sheet. I am confused by the torque curve on this sheet. Almost like the operator should have lowered the start rpm for the pulls to get the torque peak. In my opinion (which is more than likely completely wrong) I think that a 5600 to 6200 stall is too high. I am tempted to try a lower stall just for kicks but the eight (that's right Eight perfectly good converters) that I currently own are stopping me from buying another one.

There are a lot of guys on this site that have forgotten more about this stuff than I will ever know so your input and expertise are greatly appreciated.

Based on the dyno sheet your peak torque is either
right at the 4600 or before it.. so thats hard to say..
but its falling from that point

Converter.

motors never going to give what it should with that cam.
I ran a cam larger than that in a sb 416

thanks again for the responses but I the questions I asked was not "please critique my cam choice". The cam has been a constant and I am aware that it,s not optimum for the new combination but my question is based on the changes that I made with no improvement in ET.

Changing the heads, increasing the rocker ratio to 1.6 from 1.5, adding a pro stock hood scoop that is sealed to the carb rather than the old school six pac scoop, lowering the stall by 500 rpm. Last time I did that the car picked up 4 tenths! Putting on a shorter tube header which was worth 20 hp on the dyno. Lastly adding a vacuum pump.

I thought that this stuff would make a a bit of a difference. But maybe not.

With your new set up is the carb dialed in yet

All those changes allow you to pump more air through your air pump(engine) PROVIDED that it can. The cam is the cork, While the parts are CAPABLE of moving more air, the cam won't let them.

Monte