Lighten your pickup of any excess weight, spare tire, tail gate, 1/4 tank of gas, strip out the full seat and put in a light bucket seat. Any lost weight is free horse power.
well this weekend i took my truck to the local races (its a 38 gmc with a 1970 455 buick) and i was wondering how to get a little more out of it. i did a stock rebuild it has a comp cam 268h cam and a edelbrock 600cfm carb on it and everything else is stock. what are some things that could change or upgrade get a little more out of it? thanks for any and all help
Lighten your pickup of any excess weight, spare tire, tail gate, 1/4 tank of gas, strip out the full seat and put in a light bucket seat. Any lost weight is free horse power.
For starters, your carb is way too small. Stock 455's had 800 cfm Qjets on them. So you are starving your Buick. (Don't pay attention to the Chevy/Ford guys that think the 600 is big enough)
What intake and exhaust do you have?
After you change the carb, you can gain a bunch of power by tuning it correctly. Set up the distributor to get the timing all in by 2500 rpm, and set total timing to about 32 or so at 2500 rpm. Don't set the timing to factory spec.
If you need an 800 cfm carb, I have several and build them for lots of Buick folks.
Good luck.
Mark.
86 GN, all factory options, engine build in progress
72 Skylark Convertible, 462, TH 400
72 GSX Clone 464, TH400, 3:42. 10.71 @126mph best
We build GM carburetors and specialize in custom built Quadrajets
www.quadrajetpower.com
mark@quadrajetpower.com
well i have a stock intake and the exhaust is a 3" side pipe with glasspacks which the one you can buy on summit and i will probably change it a little soon. and i have a 750cfm race demon carb already would that be to much because its a race carb? thanks
Last edited by bigblock_buick; 08-29-2011 at 03:46 PM.
The 750 would be much better than your 600 for power.
86 GN, all factory options, engine build in progress
72 Skylark Convertible, 462, TH 400
72 GSX Clone 464, TH400, 3:42. 10.71 @126mph best
We build GM carburetors and specialize in custom built Quadrajets
www.quadrajetpower.com
mark@quadrajetpower.com
alright i put that 750 on and it runs pretty good except when i try to hit the gas hard it sounds like it wants to die so i let it go and push it lighty and it goes good would the jets or squirters be to big? thanks
Explain a little more about the 750 carb you are trying. It's not too big, and the accelerator pump or pumps are probably not working correctly for you.
Buicks like a lot of air flow, and setting up a carb to work on a Buick is far different than most brands, especially chevy. Since the carb is still small for your big block, you need to bring in the accelerator pump/pumps quick. If it is vacuum secondary, you need to have it come in quick. Your squirters probably are not too large.
What jets are you running?
86 GN, all factory options, engine build in progress
72 Skylark Convertible, 462, TH 400
72 GSX Clone 464, TH400, 3:42. 10.71 @126mph best
We build GM carburetors and specialize in custom built Quadrajets
www.quadrajetpower.com
mark@quadrajetpower.com
i bought the carb about a year ago from ebay new its a mighty demon 750cfm and i havn't took it apart yet, and its a mechanical secondary. i'll try to adjust them to see if it works. thanks
We now run a 950 proform carb on the red car in my signature on the mild 464 engine. Would go larger carb if I had the money.
I added higher capacity accelerator pumps, and had to change up the jetting and power valve.
You should have no power valve in front and if you have one in back, make sure you compensate on the jets.
86 GN, all factory options, engine build in progress
72 Skylark Convertible, 462, TH 400
72 GSX Clone 464, TH400, 3:42. 10.71 @126mph best
We build GM carburetors and specialize in custom built Quadrajets
www.quadrajetpower.com
mark@quadrajetpower.com
alright so far i have been helped alot with all the info, but now i checked my gear ratio and it doesn't seem right i spun the tire 10 times with both tires off the ground and the driveline spun 25.5 times which gives me 2.55. i thought that it would be higher because the guy that gave it to me said he used it in his drag car when he used to race. so could i be wrong? the code on it says c1 which is a 3.73 posi. thanks for all the help
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