Have a basic 7.4/330 +.030 with stainless marine exhaust thru-hull (silent choice), edelbrock 2.0 performer intake.
Replacing peanut heads with 049's shaved a little to try for 9.00-9.25:1 compression. No previous history, new to me boat. All but over bore just completed or in progress.
What are your best guesses as to jets and meters has q-jet (merc). I do not want to start out lean!!

Thank you in advance.

What cam, intake and exhaust? If staying close to stock, it won't need much changed. Marine setup for stock 330 Q-jet is a little on the conservative (rich) side to begin with. I have PN's for the rods, jets and hangers that Merc used for the 502's that were equipped with Q-jets somewhere. I'll try to dig it up. Someone else may have an answer in the meantime.

cam, STOCK
intake EDELBROCK PERFORMER 2.0
exhaust STAINLESS MARINE GEN ii
WILL BE GOINT TO 049 HEADS 100 CC';S ABOUT 9.25-9.5:1 COMPRESSION

I'M THINKING THOSE 502 Q-JET SPECS WOULD BE A GREAT START POINT, ALSO WHERE TO BUY?
ANY OTHER RECOMMENDATIONS?
THANKS ALL

I have in my notes but have not personally verified the following:
Supposedly:
502 Mag w/Quadrajet
Primary Jets: .070" Port Side / .076" Starboard Side (Chevy #'s 7031970 + 7031976 )
Primary Metering Rods: Chevrolet #7034845 .026"/.045"
Power Valve Chevrolet #7036019
Needle/Seat Chevrolet #7035142 .135"
Secondary Metering Rods #7042356 .0300" or #7047816 .0300" // I'm not sure which of those two.

call allstate carb&fuel injection,they are very knoledgable and will have what you need.i buy all my carb parts from them.

Honestly, I don't see anything that is going to significantly change the air/fuel demands with those mods. You might be able to get away just fine with some richer secondary metering rods, and those can be changes without disassembling the carb. Do the heads have the larger valves installed? Yes, they will have larger ports than the peanut port heads, but unless you add the larger valves and do some bowl work, the flow increase is not that substantial, especially at lower speeds. Performance exhaust manifolds will add a little, but not that much. I think the 502 jetting will be too rich for your application - you will make everyone's eyes water and soot up your transom.

BTW, those 049 castings will have 118 - 120 cc chambers unless a whole lot is milled off of them. Not going to bump up your compression that much unless you are changing pistons too. I think they have pretty much the same chamber as your stock peanut port heads. The 820 castings have 112 - 114 cc chambers or thereabouts.

Mike tkach
how do i get ahold of allstate?

Budmann ii
my machine shop said he mills them to 100 cc's and i am guessing (hoping) for a compression boost to about 9.5. And was thinking that would make diff.. Don't know about the valve size until this weekend, i am guessing they are stock small valves.
How bad do they compaire to the 2.19 ones.
I need new heads and found a very reasonable priced low milage take offs from another kind and gracious oso member.
Boat is 1987 and was used in salt at early life. Po "kept it running" if you know what i mean. Intake rotted, exhaust rotted lower end rebuilt 2 yrs ago kept same heads. I took a lot of pics of valves from intake and exhaust ports and they look terrible and water jackets looking worse for ware. If i need to replace things i hunt for the best i can find usually quality take-offs from here. Any performance i gain in process is great. My boat is always way to darn slow.
Any thoughts options i am open, making final decisions regarding now what to do, i need to get on the water

allstate carb 631 234 8327

http://www.customcarbs.com
909 947 3575

I have delt with this company many times. They rebuilt the carb (# matching) for my GT-350 as well as selling me the metering rods and jets I needed for my built 350s in my 260 Stinger Chris Craft.
Consider them an option. They were spot on on the advice they gave me on "jetting."

I hgave been away from water cooled engines for several years , i am fairley good with carbed harleys but that is a different anaminal completely.
Once i get it running how do i actually check for proper mixture? I cannot use an afr meter because of water, am i limited to plug reading and pulling an exhaust hose off each side to see coloration of residue?
Will i need to make any timing changes from service manual specs, i am going with a ngk replacement spark plug for ac-mr41t which i believe is one step cooler plug than stock.
Does anybody see any problem with milling the 049 heads to 100cc chambers?
Again thank you and any all advice is appericiated.