When I started to pull the transmission in the 93 Ranger in 2006 I didn't have an impact or compressor, and soon as i put some real twist into the first exhaust manifold bolt felt it begin to twist. I knew then if it didn't get an impact that I'd quickly have a broken stud in the exhaust manifold, so went looking for one.
Wound up with a Craftsman single hammer 350ftlb impact and a Craftsman 125psi 3gal 1.5hp/oil type motor 3.5scfm portable compressor. It broke those exhaust bolts with no problem, and I was sure glad it hadn't left one broken off.
over the next 12 years it saw light to medium duty at best, almost entirely aimed at lug bolts some shop had hammered in with a 700-1100ft lb hammer, usually forcing me to use a heavy 4way and 5ft cheater along with some choice terms for the tire "tech" who'd done it. I learned to tighten my own lugs when they'd change a tire.
More recently I had to once again tackle the transmission, and danged if I hadn't used never-sieze(although I knew to) due to needing to wrap it up in preparing for a major move, and i had also likely hammered them in good as well. After 12 years hammering on stuck lugs the ol hammer didn't come close, altho it's still good for a lot of things, simply doesn't have the gusto it once had.
I got a new stronger hammer at wmart that also failed, swapped it up to their strongest 1/2in 550ft lb (about $80) which again failed to break them. Figured it needed more cfm so got a larger compressor(also at wmart, HD was too absent when I'd go there looking for help) 8gal 150psi 4.0cfm also 1.5hp oil-less motor. Still no go on the bolts.
Went to HD looking for another impact and found a 650ft lb (almost $90) and it still didn't back em out!
I was having to lift the truck into a transmission pulling state, and put it back together and on the ground each time I had to go retool!
Put a 1/2in ratchet on there with a 4ft cheater pipe and said I'm gonna back ya out, or break ya off! Put both hands and eventually added a foot to the equation. It broke, the entire chain of pipes, ratchets, and extensions exploded into pieces falling on the ground in front of me. I saw the bolt head beside the socket, started to look at it but hesitated picking it up because I'd been using a heat gun to get it warmed up much as possible, touched it to check but it was cold. Pulled it from under the tools that were on top and it was a whole bolt, not even the one from the exhaust.
Shined a light up there and the bolt was still in, put the string of extensions together and "broke" it again, this time it popped twice. That thing was popping sometimes a dozen pops each bite, but it finally got backed out intact.
I had wound up with 2 compressors(one oil and one oil-less) and 3, 1/2in impacts. I had only tried the wmart impact once but after swapping fittings onto the Husky had used it in a dozen other attempts, so kept it and returned the Wmart one(even tho I liked it better than the Husky due to much smoother operation). Wound up with a new Wmart B&S oil-less compressor and Husky 1/2in impact. I'll give the old Craftsman compressor and impact to a nearby nephew.
I truly don't believe the oil-less compressors are any real improvement, but are only a selling point to attempt concealing the manufacturers cheaper construction. Whenever they say "new and improved" look for cheaper construction and a higher price tag
One major point about the newer ones, all had 3 forward settings but only one for reverse (which they wrote off to "you don't really need it anyway" but the Craftsman I got in 2006 had three both ways, low-med-hi.