Were the heads ever milled?
Milling other then a few thousandths can create a need to mill the intake because the gasket is no longer think enough to seal it
Found this link about the Q04 and it list other numbers. Can also use the one you have and use the part number to determine what length it is. Then add how many mm/inch to get what you want
https://www.thehulltruth.com/boating-forum/305270-serpertine-belt-crossover.html
Guessing but showing 2 belt lengths for sn 0M615 thru 0W300
Should not loosen anything else
With standard power steering 865615Q04
With compact power steering 865615Q09
https://www.mercruiserparts.com/bam/subassembly/31490/9021/110
Not saying its your issue, but many have issue with finding zero lash and then the 3/4 turn. Zero is when there is no up/down movement with the push rod. You will be able to still turn the rod but there will be no up/down
For backfire on valve adjustment the valve would have to be to tight...
Losing everything check the battery cables. Might have taken them off and was fully reinstalled
There is a 50 amp breaker on the motor, has a red button. If it is pushed in and clicks then it tripped. If it pushes in and no click then it didn't
If all looks good then need a voltmeter and...
Thanks for trying to put all the info in your statement, but this is really hard to read
I sat for 2 years
Had antifreeze in the block
Cover came loose and water was in the bilge
Was the water high enough to get up to the starter?
Not finding much on the 5.3
Do believe it does not have a distributor and if so, the timing is not adjustable. The ECM gets info from the crank position sensor and/or cam sensor
As Ted said in prior post the carrier comes with seal already installed, along with o ring.
There a many threads about the cap valve seal failing and belching lube out over the net. Mine also failed and did the same. Bought a complete bottle and just replaced the cap, all good after. Can post...
Need something that will dig deeper as it gets pulled, so a Plow or Danforth. The weight of the anchor is not so much as to the type. Then need at least 10 feet of chain (more the marrier) to help keep it on the bottom and digging
Howdy
Knowing what kind of boat you have doesn't help us. The small block gets a bit closer but still no real help.
We need to know what motor as in manufacture, actual size might get use close enough, but serial numbers are best?
When you lay the race in with just your hands, does it try to tilt?
If it does then may be out or round. Could also try to take a round file or triangle scrapper to cut just the top edge off
Might try the race in the freezer for a few hours, probably give it enough to help
