i just bought a 86 with a 305 and it has a 750 4 barrel edelbrock. Im thinking its to big for that motor. When coming off the line if just wants to bog down and runs very very rich. i dont know if it needs to be carb needs to be adjusted but i really think its to big. What do yall think???

 

I don't know much at all about carbs but I would assume you just need to adjust it.

 

Unless the engine has been heavily modified, that carb is way too big for it. You should have one in the 600cfm range. for 'carburetor size' and you can find plenty of info.

 

If the carb has vacuum secondaries, then it can live on top of that motor if it is adjusted properly. It will be much easier to adjust a smaller carb though.

 

Thanks bud. will take a look.

thats the thing, i dont know if anything has been done to the engine. If i had to take a wild guess im sure something has been done to it. Who ever owned it before me made it for a toy. But yes i agree i think its too big.

 

Are you 100% sure it is a 305 and not a 350? I know that 305's came stock in those years but the engine may have been swapped out since. Hard to tell just by looking at them, you'll need to run the cast numbers to be sure.

A simple fix for it running to rich is to put in smaller jets rather than replacing the entire carb.

 

No im not a 100% sure its a 305. The labels on the hood say its a 305. Where can i find the cast number located on the engine? i mean for that matter the truck has almost 200,000 miles on it and runs like a champ, well except for the tranny

 

Casting numbers are on the block behind the drivers side head. Major PITA to see most of the time.

 

You'll need the numbers off the back of the block behind the driver side head as well as suffix codes off the top of the deck right in front of the passenger side head and behind/under the alternator to fully identify the block. Hopefully the deck hasn't been cut.

Also, the head casting codes can be beneficial if the motor came complete from something else. Those are under the valve cover.