This is what it ran , how much is left in it

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1fastgreencar said:
34 all in at 4000 that’s what blue print call for have not touched it since the brack in
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That might be the suggestion for total, but, once in the car, those dyno timing numbers sometimes go out the window. Might want more, maybe less

Total is one piece, what is the idle timing. That will make a difference in how clean it runs at idle and off idle throttle openings. I'd guess it should have about 18-22 initial timing to run clean.

JMO, you NEVER want the timing to be all in later than the flash level of the converter on a hot street or track car.
 
I've never seen an answer to rear tire size.....been asked more than twice and that's pretty important part of the puzzle........unless I missed it.
 
crackedback said:
That might be the suggestion for total, but, once in the car, those dyno timing numbers sometimes go out the window. Might want more, maybe less

Total is one piece, what is the idle timing. That will make a difference in how clean it runs at idle and off idle throttle openings. I'd guess it should have about 18-22 initial timing to run clean.

JMO, you NEVER want the timing to be all in later than the flash level of the converter on a hot street or track car.
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I’m thinking 22 sounds about right like i said in earlier post it’s been a lot of years since I’ve messed with this stuff and thanks to all that have given such good advice at thinks to look for as soon as I hit Michigan where the car is I’ll be looking over all the things iv been told to
 
Have you pulled a spark plug to see what they look like? Might need more fuel, along with other things.
 
flyfish said:
Have you pulled a spark plug to see what they look like? Might need more fuel, along with other things.
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The looked coco brown to a untrained ear like mine lol it sounds really good and feels like it pulling ,but again just getting back to raceing from 30 years of raising family. does a torque converter slipping fell the same as a transmission slipping
 
Not really, trans slipping will get worse with heat...also make the transmission fluid STINK (pull the dipstick and smell it). Attached is a link to determine converter slippage.

Wallace Racing - Converter Slip Calculator

Note: Only because I made this mistake once....the last field is tire circumference, not diameter, lol. In other words, multiply tire height by pi (in your case 26" x 3.14= 81.68"). This will tell you how badly your converter is slipping, assuming your transmission is OK.
 
What carb came on it? I also think converter is bad and responsible for the missing mph. Is this the aluminum head version? My 408 dressed model came from them with a 825 mighty demon. That is 825 cfm wet flow, not like most other cfm ratings. So in the future it might like a bit more carb. Mine ran 12.47 at 110 back then with the stock eddy heads. If you break that rear remember to have the sprag checked in the trans.
 
1fastgreencar said:
The looked coco brown to a untrained ear like mine lol it sounds really good and feels like it pulling ,but again just getting back to raceing from 30 years of raising family. does a torque converter slipping fell the same as a transmission slipping
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Coco brown on the upper part of the porcelain means it's rich at idle and cruise. To see WOT you need to look at the bottom of the shell and look at the fuel ring, but I suspect you are rich at WOT too.
 
flyfish said:
Not really, trans slipping will get worse with heat...also make the transmission fluid STINK (pull the dipstick and smell it). Attached is a link to determine converter slippage.

Wallace Racing - Converter Slip Calculator

Note: Only because I made this mistake once....the last field is tire circumference, not diameter, lol. In other words, multiply tire height by pi (in your case 26" x 3.14= 81.68"). This will tell you how badly your converter is slipping, assuming your transmission is OK.
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Awesome thank you also the last time I cheacked the trans fluid it looked good and didn’t smell burnt
 
yellow rose said:
Coco brown on the upper part of the porcelain means it's rich at idle and cruise. To see WOT you need to look at the bottom of the shell and look at the fuel ring, but I suspect you are rich at WOT too.
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Ok gotcha I was watching a guy at the track reading a friend of mine plugs ,he was talking about the ring that you are referring to. Maybe I can get him to take a look at mine , but there Chevy guys not much love coming from them
 
furrystump said:
What carb came on it? I also think converter is bad and responsible for the missing mph. Is this the aluminum head version? My 408 dressed model came from them with a 825 mighty demon. That is 825 cfm wet flow, not like most other cfm ratings. So in the future it might like a bit more carb. Mine ran 12.47 at 110 back then with the stock eddy heads. If you break that rear remember to have the sprag checked in the trans.
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750 dp an yes I’m working on replacing the rear end with a 8 3/4
 
Ok just a little update went to the local track tnt only got 3 runs in and I cheacked the throttle opening all the way made sure I was running it out the back door I forgot to change the shift points down to 5500 but will do that next weekend best run was a 12.60 @ 104 mph on the cool side I raced the bracket race and made it to the last race . Red lighted lol
 
you say>1/8 7.95 @ 85 mph

Well if corrected engine output is 335fwhp@3400lbs/26"/3.73's your ticket would look like this>
60 Foot E.T. : 1.75
1/8 Mile E.T. : 7.96
1/8 Mile Trap Speed : 85.42
1/4 Mile E.T. : 12.61
1/4 Mile Trap Speed : 106
1/4 Mile Trap RPM : 5,126+ 18% slip=6000
Watch out for fall back on shifts, if very small or non existent
and you notice hardly any change in engine note then yes you probably have a duff verter on which your just blowing through.
losing 100hp/ 1sec in Et/10mph is poss over the 1/4.

With 440fwhp/3400>
60 Foot E.T. : 1.60
1/8 Mile E.T. : 7.27
1/8 Mile Trap Speed : 93.55
1/4 Mile E.T. : 11.52
1/4 Mile Trap Speed : 116
1/4 Mile Trap RPM : 5,613+slip
 
Hot Metal said:
you say>1/8 7.95 @ 85 mph

Well if corrected engine output is 335fwhp@3400lbs/26"/3.73's your ticket would look like this>
60 Foot E.T. : 1.75
1/8 Mile E.T. : 7.96
1/8 Mile Trap Speed : 85.42
1/4 Mile E.T. : 12.61
1/4 Mile Trap Speed : 106
1/4 Mile Trap RPM : 5,126+ 18% slip=6000
Watch out for fall back on shifts, if very small or non existent
and you notice hardly any change in engine note then yes you probably have a duff verter on which your just blowing through.
losing 100hp/ 1sec in Et/10mph is poss over the 1/4.

With 440fwhp/3400>
60 Foot E.T. : 1.60
1/8 Mile E.T. : 7.27
1/8 Mile Trap Speed : 93.55
1/4 Mile E.T. : 11.52
1/4 Mile Trap Speed : 116
1/4 Mile Trap RPM : 5,613+slip
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Thank you explained that way I completely understand, a few of my friends at the track keep saying I could us a bigger carb but iv seen about the same combo as my run better numbers with the same carb
 
Well I happen to be one that does believe in big carbs as back in the day I picked up nearly 2/10ths on my stock bottom ended/stock 2.02 headed '71 340 with a worked 850DP over a 750DP it came with, and DC. .590"/268@.050 sft cam, I ran a TA 4200stall and 4.30's. I doubt in your case it would make any difference, a 750 if worked proper can work just as well on a set up, one test for carb sizing is if you have zero vacuum on WOT its too small. I would definitely get a new converter and your issues probably will be solved hopefully.
 
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Hot Metal said:
Well I happen to be one that does believe in big carbs as back in the day I picked up nearly 2/10ths on my stock bottom ended/stock 2.02 headed '71 340 with an 850DP over a 750DP, I ran a TA 4200stall and 4.30's. I doubt in your case it would make any difference, a 750 if worked proper can work just as well on a set up, one test for carb sizing is if you have zero vacuum on WOT its too small. I would definitely get a new converter and your issues probably will be solved hopefully.
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Yes sir iv been on the phone with a Company called freak show about a converter today , I’ll be calling a couple more tomorrow thanks again
 
I picked up a full second from only a converter change, stock 383 with intake and carb in a b body, went 13.60 with...gasp... 9” ger converter. Put an 8” ati treemaster in and went 12.65. So a converter could really wake it up!
 
twayne24365 said:
I picked up a full second from only a converter change, stock 383 with intake and carb in a b body, went 13.60 with...gasp... 9” ger converter. Put an 8” ati treemaster in and went 12.65. So a converter could really wake it up!
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I ran a GER converter …… ONCE!!!!! So much slippage, took a 1000 extra rpm's to pull a slight incline... LOL. I picked up E.T. by going back to the stock 904 converter :D
 
Yea I gotta say, that converter was behind 3 different engines for a lotta years, ended up cracking the hub and going into the garbage lol
 
Back to your shifting point.
Remember This!
If it kicks you in the pants when you shifted(you are over revving the eng).

now for the explanation. if you run it past its power potential (RPM) the eng will start to nose over(slow in acceleration) and When you shift it will kick you in the pants. If you shift it on time it will continue the exceleration threw the next gear.

I bet you you will mph and et at shifting at 5500esh. I really don't think there is any power left at 6000+ rpm. It may sound cool but it will be faster shifting sooner. You have got use to the long song at 6500 and it will be tough to shift it sooner....but it will be faster.
 
Cudafever said:
Back to your shifting point.
Remember This!
If it kicks you in the pants when you shifted(you are over revving the eng).

now for the explanation. if you run it past its power potential (RPM) the eng will start to nose over(slow in acceleration) and When you shift it will kick you in the pants. If you shift it on time it will continue the exceleration threw the next gear.

I bet you you will mph and et at shifting at 5500esh. I really don't think there is any power left at 6000+ rpm. It may sound cool but it will be faster shifting sooner. You have got use to the long song at 6500 and it will be tough to shift it sooner....but it will be faster.
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Yes my friend it is tuff to shift it at 5500 it seems like it wants so much more , but I wrote down a cheack list on what I need to try next time out and shift at 5500 if the 1st thing to do
 
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