Small Block & Big Block Chevy Specific - 355 sbc bogging under load

hey guys, new to this forum but im a member of many other forums. i have a 84 chevy c10 that i have been slowly restoring, i just got it running and the engine consists of: 355 shortblock flat top pistons, dart SHP alum heads 180cc runners 64cc chambers, comp thumpr cam and lifters, hardened comp pushrods stock length, edelbrock rpm air gap intake, msd hei complete dist, edelbrock 1406 carb, still have the manifolds on the truck but has true duals with flows, have a set of headers and an xpipe going on tomorrow... the truck recently got 16 mpg on the highway driving from indianapolis to michigan and back. it runs alright, makes good power but it seems very boggy off the line. also the truck has a mild 700r4 trans in it, with a stock torque converter. i know i probably should get a stall converter but it seems like its an engine bog and not an issue with stall.

i have checked plugs and were a little rich so i leaned the carb out a little, my confusion comes from the timing. right now it is advanced somewhere between 35-40 degrees just to run! if i get it down to 16 degrees (which is where my timing indicator stops) it wants to die and runs horrible. why would it have to be so advanced just to run?

please any info or suggestions will be greatly appreciated. i have been chasing this problem for about 2 weeks now. it has me stumped.

So you're saying you need 35-40* at idle to keep it running? You didn't happen to use a stock timing cover off a 305, did you? The only reason I ask is that the timing pointer is in a different location than a 350.

i had that same timing issue on a 350 before, i never figured out why. i even used the same distributor and wires on another 350 and that ones timing was normal. you could try timing it with a vacuum gauge

Cams with alot of overlap like yours need lots of initial timing to idle good. Most camed smallblocks run best with atleast 20 degrees base timing. Sounds like a combination of low initial timing and converter being to tight. What rear gear are you running? MSD dist have bushings to adj timing lead. You will need the largest one.

Is that timing figure with the vacuum advance can connected or disconnected?

You need to set the timing with the can DISCONNECTED.

with ti disconnected, set your initial by turning the distributor back and forth. Probably in the teens...

Next, adjust the mechanical advance by using different weights and springs that come in a kit. Check Summit or Jegs for one.

After this, connect the can back up and go for a drive and see where you are at.

Usually a good idea to find someone local who knows how to do this for you and watch them. After you see it once, you'll have it down. Setting the timing on a SBC with a vacuum advance is really simple but it amazes me how many people think they know what they are doing but don't have a clue so be careful who you use.

are you sure your rockers are adjusted right?