whats the best size injectors for a 383 with all most of the boltons and ported heads? would 42 lb/h be to big? lets say i stay na and do all boltons is 36 lb/h gona cut it? i dont want to buy injectors twice, but i also dont want them so big i cant idle. thanks for any sugestions in advance.

 

so has anybody here maxed out 36 lb/h injectors n/a on a 383

 

Injector size is determined by HP and the economy of the tuning.

A rough guideline for NA applications:

24# to 400HP (yes, I know there are people making 450HP on stock injectors - not recommended though)
28# to 450HP
30# to 500HP
36# to 600HP
42# to 700HP

The only downside from too large an injector is the difficulty in tuning at idle. The very low pulse widths can be hard to achieve, and idle may get rough.