Correct jets on 2 X 4 carbs

[rstreet]

I am putting 2 X 4's on a 348 (61) with automatic/3:36 rear and am concerned that the stock jetting on the 1404(I think) Eldebrocks 500 cfms supposedly box stock will be too fat. This is for show and wow factor only. Any ideas from prior experience?

 

[Ronnie Russell]

rstreet, I assume you are talking about a stock 250hp-348. If so, drop primary jet to .083 and use the .065x.052 metering rod.( stock rods) This will drop you to 2 stages lean ( both cruise and power modes) Change secondary jet to .089. This will drop secondary 2 stages also. Any more than 2 stages lean with cast pistons might result in a burned piston. A stock 250-348 with A/T may not be happy with that much cfm, but a simple way to use them and still get the 2x4 effect is to restrict throttle linkage. Just because they are on the engine does not mean you have to use 100% of available carbs. Nobody will know but you.

 

[rstreet]

Thanks Ronnie....Yes, you are correct I will be the only one that will know if the linkage is "fooled"