Weber Power Plates - bought out by a gov't conspiracy whack job - so NO ! I have not.

Above is Fact.

The 850 marine comes with 82 in the primary and 94 in the secondary.

need a wideband 1st off, every engine/intake/cam combo different, so without seeing the AFR's you have no idea..

Got some Brand New QFT 1050's For Sale!

I use holley #9022 marine carbs. 800 cfm on my 540's, Dart Pro1 CNC alum. heads, Dart tall single plane intake w/ 1" spacer on top, mild .600 lift roller cams, Eddie Marine Thunder exh., msd ignition boxes, 34 degree total advance, i use #80 jets front,, #90 jets rear,, they run great, my spark plugs look good just a little on the rich side which is what i want, i have tried different jetting but this setup works the best for my engines, have ran this combination 7 years now with no problems.

sorry to hijack but SB you just raised a good point, I run the stock merc flame arrestor on my stock 502, is it sufficient? its the same size as the one on my 4.3 (no choke tower on mine)

I don't know. You must test.

I lost almost 3mph to a 9x4 (2.75" element height) K&N on a mild small block single application. This is the most common K&N arrestor for people to buy.

Yup, no schit. Fact.

Edit in: testing was done once the K&N was approx 6-7yrs old. No testing before that. Have gotten a new K&N same size to test if it in fact is the age or the flame arrestor itself. Losing that much MPH due to a 'simple' item is bullchit...when going for max performance.

On my new 572's w/Dominators, we put the HUGE 3" tall Billet Oval Arrestors from Hardin, ran with and without...ZERO HP Difference! Good piece! Not "Cheap" but QUALITY isn't CHEAP!!