The GMC CCKW

I need to replace the head gasket in the old GMC.

Read the manual, nothing to exciting.... anyone do this before, and any 'gotcha's' to pass along?

I plat to keep the engine in the frame and simply swap out the gasket.. no major rebuild (unless warranted).

One thing I have noted is the amount of corrosion on the valve train (studs).

I plan of cleaning that off, and 'sprucing up' what I can.

Just make sure you change your oil and filter afterwards, and regrind your valves whilst you're at it. The only problem I encounterd was with the manifold bolts, maybe get your engine warm first then loosen of the manifold bolts then leave to cool before you start the strip down. Check the bores for wear and any defects.
Have fun

If you have extra head bolts, ot can make some long studs, you can screw a couple into the head to hold the headgasket centered and to guide the head down onto the block.

If you have the original WW2 270, the circular tightening sequence. If newer (50's) then it has a weird pattern.

I tighten the bolts to about 1/3 the 1st time, then go round again and tighten them all to the same torque of about 2/3 spec. Finalld, I tighten it up to the spec.

Leave the valves a little loose.

Remember to retorque after you run it and adjust the valves

Hi,

The head is heavy. I recommend you use a portable engine puller to help take the head off and also when reinstalling. I used a 3M circular sanding disk (like a scrub brush - plastic type material) to clean the engine block super clean before reinstalling. I agree, I would have the valves reground.

The head assembly was maybe 40-50lbs. Not that bad. Definately no hoisting required. Two people would probibly be eaiser.. but I got it out myself no problems.