Re: 283 Cylinder Head Decision
 

Sweet, thank you

Re: 283 Cylinder Head Decision
 

Be sure to give those plug seats on the head a good cleaning before installing your new plugs. Otherwise you might not get a good seal. They likely have a few years accumulation of crud since you were running the newer taper plugs.

IMO - your compression numbers look good. What you don't want to see is 7 cylinders at one number and the 8th way off.

Re: 283 Cylinder Head Decision
 

Before you buy new plugs, clean up the plug seat area in the head and post a pic of the plug hole....

Also post a pic of the front of the head showing the casting pattern...someone may have put taper seat heads on this good old boy....

140 average and a 4% variance which is pretty good for this good old boy

:chevy::chevy::chevy:

Re: 283 Cylinder Head Decision
 

Ok, here's two pictures from when I first put the engine in 3 years ago. The heads have no bolt holes for accessories. They have a rectangle at the front.
The second picture shows the number one spark plug hole. My thoughts to run the tapered plug came from the beveled edge leading to the threads.

I've only done plugs on this truck, my Dakota, and my dad's 02 Silverado.

The heads on my other 283 that I pulled out have no accessory holes and have the single triangle on top of the rectangle (3rd picture)


AussieinNC,
On the sheet where I wrote down my numbers, I wasn't real clear on the spread. I had a difference in PSI between high and low of 10 PSI. I had about a 4% difference from the average in PSI at the highest and lowest numbers.


Dead Parrot,
Thank you for the tip! I was glad to see that there was not a cylinder completely out of line compared to the others

Re: 283 Cylinder Head Decision
 

The heads on the smoky engine appear to be 460 castings...8:1 compression, 1.72 / 1.50 valves....

The heads on the other engine are known as power pak heads....9.25 compression, 1.72 / 1.50 valves.....59 cc chambers...57-60 fuel injection heads....better heads but no accessory holes....

Assuming they are not cracked or corroded, these would be better heads to refurb on a rebuild.

:chevy::chevy::chevy:

Re: 283 Cylinder Head Decision
 

The ones on the engine now are 3814480 castings. Mortec says this: "3814480....60-67...283/327..70cc chambers, 1.72/1.5 valves". I don't have a picture of the casting numbers on my power pak heads, so I don't have those numbers readily available.

Most likely, I'll be replacing the valve seals with the engine still in the truck over Christmas break. Most economical and least time consuming at the moment

Re: 283 Cylinder Head Decision
 

Now that I'm back home for Thanksgiving, I checked the numbers on the other heads. They are 3884520 heads

Re: 283 Cylinder Head Decision
 

I got the correct plugs swapped in yesterday. Seems to be running a tad better now.
Haven't dealt with the valve seals yet, but since I'm headed back to Milly tomorrow with Frankentruck, I didn't want to start something and not be able to finish it