Charger3488 Posted February 19, 2012 Share Posted February 19, 2012 im building a 502 bbc and im replacing the stock 5/16 th lines to better 3/8 th. i kno i need a better sending unit everything else is a mystery to me can my fellow brothers help me? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted February 19, 2012 Share Posted February 19, 2012 depending on how potent your 502 is going to be, you are on the verge of needing 1/2" line Quote Link to comment Share on other sites More sharing options...
502ci Posted February 19, 2012 Share Posted February 19, 2012 depending on how potent your 502 is going to be, you are on the verge of needing 1/2" line ...... Â More info. Quote Link to comment Share on other sites More sharing options...
Charger3488 Posted February 20, 2012 Author Share Posted February 20, 2012 wat do u mean by potent i want it to be street/strip its a sleeper lol well as far as a 502 goes. Quote Link to comment Share on other sites More sharing options...
dbreese Posted February 20, 2012 Share Posted February 20, 2012 wat do u mean by potent i want it to be street/strip its a sleeper lol well as far as a 502 goes.  1/2" hard line or -8 braided stainless steel and this http://www.robbmcperformance.com/products/1069_gmsend.html  I have -8 braided ss feed and return with a Mallory 140 electric fuel pump/return style regulator and I have no fuel delivery issues with my s/b.   David Quote Link to comment Share on other sites More sharing options...
Charger3488 Posted February 20, 2012 Author Share Posted February 20, 2012 but this is a gas guzzuling 502 bb do i need to get a beeier sending unit in the gas tank? Quote Link to comment Share on other sites More sharing options...
dbreese Posted February 21, 2012 Share Posted February 21, 2012 but this is a gas guzzuling 502 bb do i need to get a beeier sending unit in the gas tank?  It will be plenty big. How much hp are you planning to make? Will you spray it? Will the car be just an occasional strip car or are you gonna race brackets, heads up, grudge?  Just as an example my s/b made right at 575 fwhp and 520 ft/lbs of torque on the dyno. I have made numerous passes at the track and shifted as high as 7200 rpm and the car never nosed over. If you don't want to sump your tank the Robbmc pickup is great. I just keep the tank half full at the track so the pickup tube doesn't get uncovered on the launch.  This link has good info on fuel consumption needs for an engine and fuel systems http://www.centuryperformance.com/fuelis...me-spg-140.html  David Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 21, 2012 Share Posted February 21, 2012 Are you sure your stock line is 5/16"? I thought the stock line on these is 3/8". There is also a return line- that one is pretty small. Â I'm using the stock line and pickup in my 454 Monte nipping into the 11s. I've used a 3/8" line in low 11-second cars. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted February 21, 2012 Share Posted February 21, 2012 My stock 3/8th line was good to about 11.5s Quote Link to comment Share on other sites More sharing options...
Charger3488 Posted February 21, 2012 Author Share Posted February 21, 2012 im building it for atleast 502hp but i think its gonna make awhole lot more torque is somewhere around 530ft pt. i just dnt want it to be dehydrated from lack of gas im sure the stock tank is enough i seen 454s with more hp run with stock gas tanks. p.s. can 454 heads fit on a 502 bbc i know the 502 needs more airflow no less then 305cc. yes it has a return line both are 5/16th. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted February 22, 2012 Share Posted February 22, 2012 I'm using my stock 3/8 line with a 130 gph electric pump on my 502 (stock ZZ cam). Haven’t had it to the track to see if it noses over, but it does not feel like it on the street.  Curious, is yours a newer block with a provision for a mechanical pump? Quote Link to comment Share on other sites More sharing options...
Blue502 Posted February 22, 2012 Share Posted February 22, 2012 Don't tell my motor that.I'm running AFR290s and a YSI. I always go overkill on the fuel system.Do it once and forget it.1/2" or -8 will get you well into the 10s or faster.If you need an approximate on # line size,just turn the # into 16Th's. -8 = 8/16 & -10 = 10/16.There is nothing wrong with going the same size on the feed and return but a lot of cars go one line size down on the return.-8 feed and -6 return. _________________________ quote=Charger3488]im building it for atleast 502hp but i think its gonna make awhole lot more torque is somewhere around 530ft pt. i just dnt want it to be dehydrated from lack of gas im sure the stock tank is enough i seen 454s with more hp run with stock gas tanks. p.s. can 454 heads fit on a 502 bbc i know the 502 needs more airflow no less then 305cc. yes it has a return line both are 5/16th. Quote Link to comment Share on other sites More sharing options...
Andy's Auto Posted February 22, 2012 Share Posted February 22, 2012 Â Dave Breeze recomended this one to me on my 71 and have yet to starve the 496 or the NOS system. I just piggy backed -10 pushlock to the stock line. Best $150 you will ever spend. Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted February 24, 2012 Share Posted February 24, 2012 If the pickup in Andy's picture is 1/2" it's the ticket along with 1/2 line all the way to your regulator. I sent my stock pickup out to be re-tubed to 1/2", but for the life of me can't remember who did it(would need to dig out receipt). I also believe in overkill and the do it once and be done with it theory. Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 25, 2012 Share Posted February 25, 2012 Â Dave Breeze recomended this one to me on my 71 and have yet to starve the 496 or the NOS system. I just piggy backed -10 pushlock to the stock line. Best $150 you will ever spend. Â For $150 that thing is the sh*t! http://www.robbmcperformance.com/products/1069_gmsend.html We made a 1/2" sending unit for the Camaro- no issues there with fuel. But I'd buy that one instead of making one. I love making power with a stock tank... sumps are way too "race car" for me. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted February 25, 2012 Share Posted February 25, 2012 I have one with the AN fittings. My only issue is having to keep so much fuel in it at the strip Quote Link to comment Share on other sites More sharing options...
Charger3488 Posted March 5, 2012 Author Share Posted March 5, 2012 mechanical pump. wats the best carb should i get my dad says holley but i need more detail. can i restore my gas tank? Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted March 5, 2012 Share Posted March 5, 2012 Tell us more about your 502, heads, cam, intake, and your goals. Will it be a cruiser, street/strip, or strip? It will be easier to help you choose a carb. Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted March 7, 2012 Share Posted March 7, 2012 You could restore your gas tank, but if it's in bad shape why not just replace it. There are a few companies that still make original style gas tanks for a FGMC. As far as your carb goes let me just say this, I have a Holley 170gph mechanical pump with and AED 1050 Pro-Street Dominator carb and have never ran out of fuel no matter how hard I hit it. The carb for you is as Mike says you need to give more data, but the best thing to do is to talk to a carb builder at a custom shop to have one built for your application. Even a carb like that will need a little tweaking out of the box, but it will be so close that you will spend very little time tuning it. My AED was built just for me and it was very close right out of the box. If you have a street car that might see the occasional run down the strip on a test and tune night you will more than likely end up with an 850, or possibly a mild 950 carb. Don't forget about your air cleaner as CFM airflow will be hurt by a run of the mill chrome air cleaner. I recommend a K&N air cleaner assembly that clears your hood(may need a drop base style) with an Extreme open element lid. More airflow than you will ever need. Quote Link to comment Share on other sites More sharing options...
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