So, I finally traced my coolant issue back to the intake manifold. I am in the process of getting everything out now and it started raining so I am using the rest of the day to regroup.

I am running into incomplete information online about the torque and sequence of tightening the bolts and I want to make sure I get this all clear.

This is the 4.3 Vortec engine with the spider.

So far I have found this diagram for the lower intake bolts as far as tightening order:

Distributor
5 6

3 2



1 4

7 8
Radiator

The only torque info I have found is that it is a 3 step process in Inch (not Foot) Pounds.

1) 27 in lbs
2) 106 in lbs
3) 133 in lbs

I've read that this applies to both upper and lower and that just doesn't sound right.
Also, what is the tightening order for the upper part?

 

132 in pounds conversion is 11 ft pounds if you don't have in pound torque wrench

 

Yes I know the conversions but what are those pressures for, the lower manifold or the upper part? Its just odd that they would be the same given one is metal and one is plastic.

 

The threads in the cylinder heads and bolts must be cleaned using a tap & die, and thread sealer applied before installing the bolts.

The upper intake, (plenum) is torqued in a criss-cross pattern, starting in the center, in two steps. First step is 44 inch pounds, second step is 80 inch pounds. Threads must be cleaned and sealer applied to these bolts too.

The reason for cleaning the threads is so the torque is accurate. The reason for the sealer is to keep the bolts from "walking out" due to the low torque.