400 block Question
 

the 400 in the 69 camaro we have has bosses where the drivers side low mount altenator brackets holes normally go...My question ('s) for you guys is this.
#1- how much block material is behind these bosses for drilling and tapping ?

2- what would be some ideas on drilling and tapping this bosses..without the obvious ( tearing motor down etc...).....

i do realize this is not the perfect senerio for the hand drill etc....

i was thinking maybe some of you guys have done this job while engine is still in car and make yourself a makshift jig or something.

thanks Brian

Hey BJ,
if you have a drill press, drill thru a 1/2" block of steel then clamp it over the boss as a pilot hole. Useing a 5/16" drill/3/8" tap drill. I think you can safely drill 5/8" deep after it's drilled open up the guide plate to fit the tap and bottom tap with a 3/8 X 16 tap, then put a stud in the tapped hole, this will keep everything square.
If you have a 90 degree drill it will be a lot easier if the motor is still in the car.
A couple yrs. ago we installed a 400" blk in a dragster, only to find afterward it wasn't drilled for straight across starter bolts. I made a guide plate grabbed a 16" long drill from the shop and had it bolted up in 1/2 hour laying on my back on the garage floor.

JMO

Zip.

notes taken..thanks zip.
brian