Ok since this is something that seems to get some attention here let me post my stuff and see what you guys think. My car is down now for some maintenance and improvements, one of the things I am considering is a gear swap.

Here is the currect situation, sorry this may get winded but may help some come to a conclusion. I am currently running a 4.30 gear with a 15x33" Goodyear slick. On the odd occasion I run the car all out these days I cross the traps at 7500rpm. Sounds all well and good until you consider my engine makes peak HP at 7600. When I am on the stop the trap RPM is a tad less. As an indication of how the car reacts to more RPM when I run the car all out and shift at 7600 the car runs .3 slower than when we shift at 8300. The trap RPM of 7500 is from when we shift at 8300.

So with that little bit of backround my question is what should I do, or better yet what would YOU do?. I can leave it as is, I figure it is a bit less wear and tear on things with the lower RPM. It works very well as it is, but I KNOW I am giving up ET and MPH on the stop. The car is just really starting move about 1100' downtrack all out, on the stop it is starting to pull hard just before the lites. So given the parametrs what gear if any would you go to if any a 4.56 or a 4.88? With more gear I could improve my aenemic 60' times as well. The car has been in the 1.teens a couple of times but usually is a low 1.20 car. One more little tid bit that I have heard from a few different folks running all out is this comment. Man your car really starts to move about 4-500'out, which is true. The timeslips confirm, my 1/8 mile stats are not really on par with my 1/4 mile numbers.

So what do you all think..Looking forward to hearing your thoughts on all this.

What is your current MPH? Power-glide?

Al, You don't really seem like the kinda guy to leave that ET on the table. You paid for all those ponies, might as well put the gear in to use them.

Especially if you are going to be racing the car on the stop more regularly, I would go to a lower gear.

It looks like your converter is slipping a whopping 4% with that gear.

4.88s will put you about 8600 RPM.....figuring you pick up to 166 MPH.

4.56s will put you about 8030 RPM at the same 166 MPH.

Also with a lower gear, it may not need the 8300 shift for best ET either.

I would not want to spin any bb 8000rpm+ on any pass, but that is just me. I need my stuff to live a long happy life!
Your car and my old 555ci Dart combo are nearly indentical in weight hp, and et/mph. I ran the same tire also and with 456gear I was hitting 7800 and I wasn't to0 happy with that so I changed to to 4.30.
Have you got the chassis straightened out so you can run consistantly off the stop??
My advise, like anything else you just need to test. My new car responded well to 4.30 gear from 4.10. With the 555ci it went `1.18-1.19 and gear change netted 1.134 in nasty racing conditions. Big motor is now in and should go 1.0x pretty easy, that is with big 34.5 tire and beadlock as well.

Wayne, don't you run methanol?

4.56.........final answer.

I'd go with the 4.56, it would pull a little harder
coming off the stop and it wouldnt be ringing it too
much and still leave you room if you werent on the stop

Call Dewco and ask them what they have in the range you are looking for. They have some matched stuff that really works well with certain ratios-for several reason. Be prepared to open your wallet but in this case well worth it IMO.

4.56 is what I had in my Cuda when your motor was in it.

P.S. Those exact gears (Richmond Pro 4.56 Ring & Pinion) are sitting in a box, about 10 feet from me. Say the words and they will be on there way to you......

(Technicnally they are a 4.57.....Part#79-0080-1)

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I would not want to spin any bb 8000rpm+ on any pass, but that is just me.

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no it isn't just you. i'm no crack engine builder and i know a properly sorted engine will make HP up there but i just don't think it's a good idea. i don't recall what his combo is (guessing 4.5 stroke?) but one would have to think the piston speed is up there pretty good at 8300. iirc this engine was done by a high end builder but still for a bracket type (that is what it is) car imho that's just too fast. SS/comp type engines that are looking for every last hundredth and get torn down frequently is one thing. it sounds like the engine was specd to turn that fast but i think it's hard on parts especially when you're just slowing it with the stop anyhow. it sounds like performance wise it would react favorably to the 456 but again it is a bracket car. i'm assuming this has a 1.80 gearset?

Jamesc,I don't think Al motors is anywhere near a bracket motor, it was built to run heads up with nn break out. Al ism just crazy enough to run it in a break out class It is his stuff, he can do what ever he wants with it Al, what low gear are you running in thr trans? Maybe thier is some 60 ft. times thier . A swap from 4.30 to 4.56 is a 5.7 % change, is that enough for you or do you want more like going to a 4.88 which is 11.9% A shorter tire can accomplish the same thing, especially on the stop

i was under the impression he built the car to run SST (am i wrong?) which is a far cry from a heads up class pro tree or not. building a car to run heads up and SST seems like a tall order as it probably wouldn't do either very well. i didn't say it was a bracket engine which is why i mentioned the combo was specd with the intention of turning it that fast. i'm not suggesting that my opinions are what he should do or are any more valid than another. he asked for thoughts and i gave mine. i still say at those crank speeds it's turning too fast for a bracket car which is what SST is.

Al am i missing something here? if you're engine makes peak hp at 7600 why are you shifting it at 8300 not to mention you say it's running .3 faster with the higher shift point. i was always under the impression it was best to shift at or slightly before the peak HP point

Well James the car is used in S/ST and seems to work really well that way. We have done ok to this point running it this way. On the stop the car is pretty lazy but still runs a fairly big MPH in S/ST trim. It does have a 1.80 gearset PG. As for it not doing well it has done me well so far this year with a limited amount of testing time on the stop. We did R/U at a Divisional race a few weeks ago so it must be ok right? I appreciate your input and agree with much of what you say. I guess it is my closet desire to have S/ST and T/S on my windshield at the same time

As for the engine itself. It makes well over 1000hp from 7200-8500, peak hp is pretty steady from 7500-7900, 7600 is where the highest TQ is with the 1040hp. When the pull was stopped at 8500 it was still over 1030hp. It is NOT a torque monster for sure.

IMO the reason for the ET difference is shift recovery, when I shift low the RPM drops to far to keep the motor happy. IMO a gear change wouodl also have a great affect here as well. Just a matter of the time it takes to get the engine back to where it is happy and pulling hard again. Simple as that, and there is a significant difference. I also agree a looser converter would possible help but the one in it is pretty loose as it is. The engine builder and myself agree for all out it could stand to be a ton looser than it is. But hey I am a bracket guy and this one works pretty well. I dont have the info right in front of my but it is enough of a difference it affects the ET a good deal. My stroke is 4.125 so the engine likes the RPM for sure and is built to run that way. I just looked at a Data log and last time we had it hooked up for testing I was crossing the line at 7200 on the stop. Given that most of the time for the forseeable future it will be raced on the stop I am a bit reluctant to change the gearing. Although I spend 5 seconds of a 10.90 run at 4300rpm, with a gear change I would imagine that time on the stop may go even higher. I would not mind another MPH or two on the stop with the side benfit being a little quicker all out as well more than likely.

I was going to go with a 4.56 gear but was fearful it would be a change that will most likely not net much gain. That was why I was considering a 4.88 instead. Figured that was enough of a chnge to see an appreciable difference. Otherwise in my mind it is not worth the effort or expense. IF I had a set of 4.56's that were here I may do it but I dont and if I am buying I was leaning towards 4.88's. My thinking was that will give me a better SLR and will most likely pick up the 60' and the cars reaction when and if I feel the need to run Gas or Comp.

Chris...Remember while you ran a 4.56 gear in your Barracuda your tire is 29" tall while mine is 33" tall, a BIG difference.

Keep it coming guys I am listening.