I'll try setting it back but don't think it will run that far retarded. The distributor came with a set of heavier springs so we'll try that to. Thanks for your input and we'll let you know if it works.

 

Any update on the overheating?

 

Yeah 10 deg is way to retarded started it tried turning it back and couldn't get close to 10 deg. It runs great at 24 deg vacume pluged. Haven't tried the heavier springs. I don't get it at 24 deg it idles nice strong acceleration and maintains at or below 200 deg temperature unless it's at idle or city traffic. You think going 30 over on the bore was to much. This is the first rat motor we built. 400 ci small block. I did notice that when im at a stop the trans seems to be engaging tring to take off. maybe going to a higher stall in the torque converter would help. The only other thing i can think of is a couple electric fans

 

Do you have a double roller timing chain, if so was it advanced or retarded?
What is the idle set to?
With light springs the advance could be kicking in at idle throwing everything off, definatley try the heavy springs first

A standard 1968 - 1969 Pontiac 400 timing is 9 degrees
A 1969 RAM AIR IV - which has a monster cam is 15 degrees

https://www.tpocr.com/pontiac1.html

 

Stock setting 1976 pontiac firebird formula 400 is 16 deg btc with vacume plugged. Yes double roller chain not sure exactly where Wayne's set it. But when i called Melling the cam manufacturer they told me to set it at 24 to 26 deg. Idle set at 650 or 700 rpm. I will definitely try the heavy springs Friday when my son comes over and let you know how it turns out. Thanks again for your input.

 

the 24 to 26 deg was initial timming whith vacume plugged

 

A factory 1976 Pontiac 400 had 12 degrees.
24 to 26 is way too much initial timing

What cam do you have in there?
Pontiac firebird; timing, spark plug

 

You shure my book said 16 btc ok I'll try 22 btc. The cam is a Melling mtp-1

 

Yeah just looked timming up 12 deg is for manual trans 16 deg for automatic