1970 LT1 Intake Manifold Bolts

[George C.]

I have "M" and "NAT" headmarks on my intake manifold bolts.

Will that pass NCRS judging?

[Terry M.]

Re: 1970 LT1 Intake Manifold Bolts

I have "M" and "NAT" headmarks on my intake manifold bolts.

Will that pass NCRS judging?

The NAT would not. The M might depending on other configuration issues. That is if I were judging the car. Others might offer different opinions. BTW the bolt head marks would, at worst, be a minor deduction.

[George C.]

Re: 1970 LT1 Intake Manifold Bolts

Terry,

Someone said the NCRS judging guide says "C" and "AL" headmarking on intake manifold bolts.

Were do you get C and AL bolts?

What configuration issues would make "M" headmark acceptable?

[Gary B.]

Re: 1970 LT1 Intake Manifold Bolts

The new NCRS TIM&JG says "Common headmarkings are C and AL." It does not say these are the only headmarkings seen. 1970's are often seen with "M" headmarks, later years are commonly seen with "C". Other headmarks have been seen. "NAT" is often seen on valve covers and alternator adjusting bolt. If I owned a car with M and NAT intake bolts, I would leave it alone. I think you would find most judges would not say a word.
Gary Bosselman