Fuel pump fitting size 1970 L78 stock fuel pump

[396L78canuck]

I added a one inch open spacer under the stock 4492 Holley for my 1970 Nova with L78 and stock AC delco fuel pump and wanted to purchase a fuel line kit from the stock pump to the carb to replace the metal line that is now to short.The sales rep at Summit racing is asking we the inlet thread size for the stock AC delco pump.From what I can measure it looks like either a 5/8 or 9/16.Does anyone on the site know for sure.Thks Bob

[WILMASBOYL78]

If you are using the 1970 #569 intake (pancake style) then the spacer will raise the carb up enough that a 1969 fuel line may just work for you...of course the junction block and small tubes are also different for 69, so you would need the whole setup. The spacer may not be as high as a 1969 #163 intake, but you can probably tweek it to work. This may be a simple solution and also afford a "stock like" appearance....hope this helps.

wilma

[olredalert]

------Yah,,,You can probably make all that work, but I dont think you would help the underlying problem. And,,,that is that the low L78 1970 manifold is an under-performer due to the low height of the plenum under the carb. Raw fuel tends to puddle up in there and the flow is bad weather you have a spacer there or not. I hope Im not too strident here, but get a #163 intake and then get the fuel lines and pump to match.........Bill S

[WILMASBOYL78]

Bill, I agree the #163 is a much better choice for performance if originality is not critical. Since he is using a non-original spacer I can only assume it is not an issue. I have seen some respectable dyno numbers using the flat manifold....425-430hp with stock L78 specs. We have the 163 on our 70 TH400 L78 and it seems to work great....I'm not sure the average guy can tell the difference on the street...does anyone have any dyno comparisons #163 vs. #569..???


wilma

[Mr. Chevy]

Bob, I believe that should be a 3/8 fuel line just like the tank to pump line is.. I don't think it was down sized from the pump to carb.. All the high horse/big block motors had the 3/8 line in 68-70

Also if you go to this thread: 1970 Nova L78 Intake '569' - perfomance!!
#400353 - 04/30/09 07:00 PM
it discusess the performance issues with the intakes..

Rich

[396L78canuck]

Thanks Guy's .I ordered a 69 setup and will try to tweak it to fit.I originally thought the 69 intake was more than inch taller than the 70 unit.I agree that the 69 is probably worth a 10 to 15 HP over the 70 unit.Bob