72 C10 for my 25th wedding anniversary

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Originally Posted by raggedjim

Great thread, you have done some good work on this truck.

Good luck, Rg

Thanks
And thanks for taking the time to check it out

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When ordering pushrods, I found that most of the time if the cam and springs come in a kit, the pushrod supplied is 5/16 x .080 wall.
I wanted just a bit extra …. My first choice would have been a set of Manton 502’s 11/32 x .120 wall but they are close to $400 and I still needed to upgrade the lifter trunions, so not right now, but an easy change later.

I did check out Trend and Smith Bros, but couldn’t find that they currently sell 11/32 pushrods . They must have a few years ago because I found articles from 2020 saying guys were running Trend 11/32 pushrods and liked them. Smith had 7/16 but I don’t think they fit without a little work to the heads. I know the stock 243’s and 799’s need the pushrod holes opened up a bit to fit 3/8, but that would likely be overkill for this little engine at this point.

Second choice was a set of Summit Racing 11/32 x.120 wall pushrods, and I did read in multiple articles they are made by Trend. But they are out of stock until 4/10/24
Third choice and final choice was a set from BTR . They are 11/32 x.080 chromoly, not quite what I wanted but still a bit stronger than 5/16 and a fair compromise on price and they were in stock.
I also ordered a trunion upgrade kit from CHE precision, they have very good reviews and do not require any special tools to remove the old or install the new trunions.
Both items should arrive by 2/20/24, looking forward to getting the rest of the engine back together.
Next I would like to do something with the coils, I would like to hide them with coil covers, but have found very few covers that look like they fit well for use with the round “heat sink” truck coils (D585 coils).
I also think I want to make the remaining portion of my exhaust 3” if I have the room
Still a bit of time before good spring weather, hopefully spring comes early this year. Can’t wait to get out and drive the truck again

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Pushrods arrived today, but the Trunions are delayed, looks like they won’t be here until Friday or Saturday now.
I thought since I had a bit of time, I would press the old trunions out of the rockers and get them ready for the new trunions and bushings.

First I gave them a quick rinse in the parts washer to get rid of the old oil residue
Next since I don’t have a press yet, I made due with the vise and a couple of sockets. I removed the teeth from the jaws of the vise, so I wouldn’t damage or chew up the socket. I turned one around to the smooth side and left the other off, as it provided a lip on the bottom to hold the larger socket in position. I used a 7/8 socket on the side of the rocker that has two small flat spots( the larger socket just fit better there) this side receives the trunion. On the opposite side I used a 9/16 socket to push the trunion through. After making sure the sockets were centered, it took just a couple of turns to press the trunion out, releasing the bearings. I kept one hand under the rocker ready to catch the parts as the trunion came loose from the rocker. They just fall apart in your hands really. I had a small container to toss the unwanted parts in, otherwise there would likely be hundreds of needle bearings scattered everywhere.

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Few more pics

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The CHE precision Inc trunion kit arrived. I had just enough time yesterday afternoon to give the rockers a final clean up, and prep for the new trunion install.
The instructions that come with the kit are very easy to follow, a simple process. There are also quite a few videos about this install online, but they are all pretty much the same. One thing the instructions mentioned is how to orient the snap ring, with the sharp side facing away from the trunion /bushing. It can be a little bit difficult to tell which side to choose, I went with the side that seemed “less” sharp. You can use oil or assembly lube when installing the trunions and bushings, I chose to use assembly lube, as it may be a while before this engine is fired up again.
Again this was a simple installation, I chose to upgrade the rockers because of the miles they had on them, not so much that I was concerned about getting rid of the needle bearings in the original trunions. With the higher lift cam and 660 springs, I felt the rockers needed some attention too. You know what they say about “New power on Old parts……This kit should compliment the new higher lift cam and stronger/stiffer springs

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Few more pics

I chose to bag up the rockers for now , rather than install them, as the assembly lube tends to collect dust , and I may have some work to do on the valve/rocker covers .
I haven’t found the coil covers I like yet that will fit the heat sink (D585) coils.
I may end up modifying a set from Jegs, Speedway, or possibly Holley . This would be my first choice, as it will hide more wires . My other thought is to just let the coils show, but clean up the wiring a bit, maybe add some braided loom, and get rid of the ugly steel bracket. I am thinking about grinding off all the existing bosses/ standoffs and welding new ones on lowering the coils about an 1”
Not sure on that yet, but will have to decide soon
I did order some new bosses/standoffs, (just in case I go that route)from McMaster-Carr. They were way cheaper than Bung-King or Boyd Welding for these items, and shipped fast, I had them the next day!

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So I haven’t been able to find coil covers to fit the D585 coils, they are big and long, so need to be mounted at a pretty good angle to mount under a cover . Then it would take new plug wires. So until I find a set that I like, or buy different coils, I decided to modify the existing valve covers.
I ground the existing bosses/standoffs off and decided to try using the valve cover bolt for one side of the coil and weld 8 new standoffs on for the other side of the coil.
My youngest son works with more aluminum than I ever have, and he told me to use wax lube on the cutting wheel, and it would cut a lot better and faster. He was right. And since I can’t weld aluminum I brought the covers to him so he can weld the 8 new bosses in place. Hopefully they turn out good.

More in a bit

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In order to use the valve cover bolt locations to mount 1 side of the coil, the valve cover bolts need to be longer, and I needed to cut the existing bolts and save the sleeves. The new longer valve cover bolts are needed so a spacer can be added to the top of the seal/sleeve to make up the difference in height from the new standoff on the opposite side
It was also a good time to replace the seals as well.

Hopefully my son will have time to get the covers finished this week.
Not sure if I will like this solution to try to clean up the look a bit or not, but time will tell.

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One thing I forgot to add in , is the need to shorten ( or buy new) rocker arm bolts for the rockers that will be used for the intake valve.
This is needed only on aftermarket heads, or heads that have been ported. When the heads are ported , and material is ground/removed from the intake runners, it is common for the area around the rocker arm bolts that protrudes into the intake runners to be opened up. This tends to leave the tips of the stock rocker arm bolts exposed and protruding into the intake runner, and potentially obstructing air flow.Research shows Comp cams and Edelbrock sell shorter bolts, but I just chose to shorten the stock bolts. The stock bolts needed almost 3/8th” removed to keep them from protruding into the intake runners, and the tip of the bolt isn’t threaded for the first 1/4”, so I cut off the tips plus 1 full thread.
When installing the rockers, the intake bolt needs to be sealed so that oil can’t be sucked past the threads and into the intake runners. I used ultra black RTV silicone.
The exhaust side is still a blind hole so it doesn’t need to be shortened and can use just a small amount of blue loctite, or nothing at all.

I didn’t want to wait any longer, and needed to get something done on a day off , so I installed the pushrods and rockers, making sure to use assembly lube on the tips of the pushrods and rockers.

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Small progress while waiting on parts……

I had been putting off torquing the HB bolt , it can be difficult to achieve the necessary torque without a big torque wrench. To make certain the HB is installed completely, it needs to be torqued to 240 ft pounds. Then the old bolt is removed and a new bolt is installed and torqued to 37ft pounds +140 degrees. I made a mark on the bolt and a impact socket. I then taped up the face of the Harmonic balancer and marked it out from the 12 O’clock position , 3 O’clock , 4 O’clock, 5 & 6 . This way if the balancer moves a bit I could still tell where 140 degrees was, which is just before 5 O’clock if starting at 12 O’clock.

With the transmission in gear and the initial 37ft pounds torqued, I started with the line on the bolt and socket lined up at 12 on the balancer an turned the bolt to just before 5 o’clock. This takes considerable effort, the final torque ended up at 245 ft pounds, but is kind of irrelevant for this TTY bolt as the degrees are more important in this case to achieve proper bolt stretch and final torque. My 1/2” torque wrench only goes to 250 Ft pounds, I may look for one that goes a bit higher and is longer for better leverage, possibly stepping up to a 3/4 drive ? Not completely necessary, but would make the job easier.
If/when I take the balancer off again for any reason I think I will just go with an ARP balancer bolt, they are reusable, and just get a torque spec. This time I had a new GM TTY bolt on hand because I ordered 2 a few years ago .

I also added a Sneek peek of the valve covers, my son sent me a pic a couple days ago. He’s not quite done yet, he is very busy at work and has side work he does in the evening at home, that plus a 10 month old baby boy makes for a challenging schedule. I do appreciate him taking time to help with my projects.

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The original coil harnesses were getting hard and brittle, I didn’t think I could modify them or move the big main connector back towards the firewall more out of sight.
The Holley coil harnesses are made so that the connector is towards the rear, so that was a plus. Summit had them on sale, so they weren’t that much more than others. They still were kind of expensive for what they are, but new harnesses were necessary.
More in a bit……

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Since the radiator was empty it was a good time to add a zinc anode, just as a precaution /cheap insurance. I have never had any sign of electrolysis, and always use distilled water in a 50/50 antifreeze solution, but the anode was only $12 on sale,so why not. It just replaces the drain petcock

I’m not sure if I like the new look of the coils and harnesses on the valve covers, in time it may grow on me. My son offered to have them powdered coated for me, but I chose to leave them raw for now, because I may weld on a AN fitting to loop in a catch can. But I would rather pull PCV from the valley I think. I have been trying to buy a Ls6 valley plate so I can pull Pcv from the valley rather than the valve cover but every place I have tried has been sold out for almost a year now.
I still think a nice set of coil covers would look good.
I can’t afford a new FAST intake or throttle body yet to complete the mods, I’ll have to wait a bit longer.
Next up is to fill all the fluids and fire it up.

[cornerstone]

I think it looks

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Originally Posted by cornerstone

I think it looks

Thanks
They are starting to grow on me. At this point I will be running them for at least this summer, or longer. It would be expensive to change to coils that will fit under the coil covers I have found that I like. That money could go towards a larger throttle body, and then I will need a different intake…..

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The cooling system was filled with nearly 3 gallons of coolant, filled through the top radiator hose so that the block and heads were completely filled first. Then the balance of the coolant filled the radiator.
Then 6 quarts of oil with zinc were added to the crankcase through the priming port in the front of the engine just behind the timing cover on the driver side.
As before I used a simple garden sprayer with a hose barb and a fitting from ICT Billet. The last time I used a larger 2 gallon sprayer, this time I used a 1 gallon sprayer. Both work equally well the smaller version is cheaper, At just $10, but the hose is plastic and is very stiff and doesn’t straighten out easily. It also requires the end of the hose to be heated with a heat gun in order for the hose barb/fitting to be inserted into the hose. I recommend checking out the quality of the hose if buying another sprayer. Otherwise both produce adequate pressure to prime the system.
More in a bit….

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The mechanical pressure gauge shows the sprayer produced enough pressure to force the oil through the system, it may have been able to produce more, but I didn’t have a clamp on the end of the hose and didn’t want the fitting to blow off the end. As far as the larger sprayer producing greater pressure, I think they are very similar, the first pick is from the smaller sprayer used to prime the engine this time, the second pick is using the larger sprayer 2 years ago, pretty close to the same.
I did release the pressure and remove the pressure tank before the oil ran out so that no air was forced through the system.
With fluids in the system, I left the same tune in the Holley Terminator from the previous setup. After waiting for the fuel pump to prime I turned the key to start, and the engine fired instantly. Oil pressure was instant as well, which was a relief given the process of installing the O ring, pickup tube, and oil pump different this time, given the inability to remove the oil pan out of the way.
After checking for leaks the RPMs were varied as the engine came to temp.
I may have to raise the idle for this cam and possibly a few other things in the Terminator, but otherwise initially everything seems great for a first fire up.

I think I may have a Pro tune the Terminator once I have installed a different intake and throttle body, in order to optimize the mods and not leave power on the table.
I haven’t been able to get the truck out yet to let the Terminator learn. After an unusually warm and brown winter, we endured a winter storm producing a lot of snow, at least 16”. So now it must melt, warmer weather is forecast for the end of next week, but I like to wait until after a good rain, so that the roads have had a chance to have been washed clean of the salt.
Can’t wait till then.