a little background on this project. I have an 85z that i converted to from Computer controlled Carb 305 to regular 350. Bought 350 short block 70kmiles from local shop (tabercorvetteparts.com) and a set of 882 heads newly rebuilt. i left the stock cam in but installed new lifters pushrods and roller tip rockers. A standard distributor out of a 77 corvette. Using a edelbrock performer EPS manifold with an edelbrock 600cfm carb,hooker headers and y pipe with a 160 thermostat. temp guage always stays about 1/4" below 220. i had noticed after a long drive (10+ minutes) it was really hard to restart (and also had no power even when cold). today i noticed when it did this the gas was in the top of the carb literally boiling and when i tried to start it backfired and caught a small fire on top of carb. i put it out and went out and bought a new carb because i was told it was a carb problem well a brand new out of the box edelbrock carb does the same thing. the only thing i could think of for this could maybe be the choke tube in the middle of the intake should i block that off. this is blowing my mind....

 

Whats the timing set at?

Is it only hard to start when hot?

Sounds like the timing is too far advanced.

 

6btdc the shortblock was out of an 84 vette so i am using those specs
super easy to start when cold one pump and shes running

 

sounds like timing to me too.or at least the hot restart does. boiling fuel problem....you might try a thicker gasket under the carb.

 

i used the stock gasket that came with the edelbrock carb going on an edelbrock intake. i have a older weiand stealth could this be a better intake to use?

 

the gasket i use is about 3/4 of an inch thick, it insulates the carb from the intake pretty well. as far as what intake is better....depends on the use of the vehicle. im using a stock winters, but i need low rpm torque and dont push to the higher rpm's. nothing really wrong with the wieand or eldelbrock in my opinion. a carbon fiber spacer would help insulate the carb also. another thought is the exaust cross over, is it blocked off or do you need it. might go with 12 degrees btdc on the timing and see what that does for you. hope somthing here helps, been there and hated it.

 

that is one of the things i was concerned about do i need the exhaust crossover on the intake? how would i block it off. i was told by friend this was my problem but never had this happen before but then again last engine i tried to build was in 92 on 69 camaro.......so intakes have changed since then

 

i dont think all intakes have the cross over but i may be wrong. the last gasket set i got (last weekend) has resrictor plates for the cross over which i will use. do you need the cross over? i dont think so, hopfuly if im wrong somebody will correct me.

 

In the 80s GM used the 3 line fuel pumps that had a return to help stop that on AC cars, non AC cars got the regular 2 line pump.

The exhaust heat riser cross over won't make it that hot or do that, though many block it off when apart, I was told by a GM engineere its ok to block off but leave a 1/4 hole if I drove in winter to help keep the intake warm, a warm intake atomizes fuel better.

 

out of curiousity... how close are your headers to the fuel lines on the passenger side... had this problem with mine. header wrap and some"judicious relocation of the fuel lines FTW!!! Lol.