Just wondering if anybody knows what the book calls for in hours to replace an engine. Basically a long block?

 

Unfortunately I don't have the factory times for these operations, only the manuals for the work itself.

Engine changes are largely dependent on experience and workshop equipment.
Also on make and model. Then it comes down to what the shop knows which shortcuts work best.
In addition it will be depending on how much stuff you have to move from the old engine to the new one and in which working condition this is.

For my 1994 Blazer I would go with about 12 man-hours, about 2 days in a shop where some time you have two mechanics work on it.
Including troubleshooting, unrelated repairs and modifications I would go with an assumed 18 man-hours of labor, make it 2 - 3 days in the shop as you have to cope with interruptions and other work interfering.

Some examples from personal experience.
1994 Blazer - get the old engine out 6 hours plus 2 more hours for all the stuff to come off the engine. 3 - 4 hours to put all the stuff back onto the new engine. Mind you I'm talking well done job, chasing some threads, using new gaskets, replacing hoses, wires, fixing broken stuff.

The way I pull engines on the Blazer is by removing the fan, radiator shroud, oil lines from engine and transmission to the radiator, then the radiator itself. Remove the air filter, TBI, (spider, injection) hoses to/from engine. Remove the distributor in order for it not to hit the firewall.

Lift the Blazer. Remove the exhaust, including Y-pipe and cat. Support the gearbox, remove all links and wiring/hoses from the gearbox (automatic transmission) driveshaft(s) (4x4) and the crossmember with the gear support. Now you can loosen the engine mounts and tilt the engine down/backwards by lowering the drivetrain. All bolts out between transmission and engine, separate the drivetrain from the engine and pull the transmission. On the 4x4 with the front driveshaft out of the way get the oil cooler hoses (if it has oil/water heat exchanger) out.

Lower the Blazer (yes I'd never do any of this without a proper garage lift) remove the hood if not already done, hang the engine on a crane, cherry-picker or other useful lifting equipment. Completely undo the engine mounts and pull 2 inches to verify that it's not hanging by any wires, hoses, or other. Pull the engine.

Now carefully compare old and new engine. Check all the mounting hardware, supports. Also check on the body and while you are at it check the steering gear box (oil fill) front differential (also oil fill) all the plastic stuff, hoses etc. in the engine compartment. No sense in putting a new engine into an engine bay and two months later you have to replace the steering gear box or some steering linkages or knuckle *****. Check all the wiring harnesses in the engine bay for chafing, damage, corrosion and fix properly. Most problems with new engines come from here. Bad sensor wires, wires get kinked, squeezed when removing the engine.

Then start removing the required stuff from the old engine and put it on the new one when they are side-by-side. There will be stuff to repair for sure. It's here where you can make or brake an engine swap. Make sure all openings into the engine are closed (clean rags, taped over). My engines come pre-primed with oil when I have them out of the car a first time, so I can make sure all works as expected. Latest before starting up you have to prime it anyways, else you would damage a new engine. As the engine is out of the truck I usually make a 10 mm stainless steel rod which fits into the oil pump slot, long enough to be able to be driven with a drill and in addition turn a nylon bung on a lathe which fits into the distributor hole to guide the rod on top of the block.

Now in reverse order the engine goes back into the Blazer with new engine mounts, bolts, transmission mounts, gaskets. Once all is back together I fill the fluids, prime the engine, follow purge procedures for the transmission and radiator, then prime the engine (not to forget a new oil filter on the engine or remote location). When all is connected properly and hooked up you can turn the ignition on and while priming observe oil pressure light to go out and oil pressure indication if fitted. Last checks over the engine and all the work, then start it up.

Some other cars I have done or helped with:
Porsche Carrera GT3RS (all quick connectors as it is a race car) 45 minutes and the engine is out.
Ferrari 512 BB (when you don't know how, 6 - 8 hours - If you know how and have the equipment and a crane (not a cherry picker) 2 hours.
Alfa Romeo Alfetta GTV (my 1978 restoration project) about 3 hours
Ferrari 250 2+2 (that's a 1953 car) about 4 - 5 hours to be extra careful
Modern cars take more time. It depends on the model and on how much stuff you have to move from one engine to the other.

Hope that answers your question and maybe somebody has the factory shop times.

 

I would need the specifics on your Blazer (year, 4x4 or 4x2, auto or manual, engine, etc.) to give you the exact time, but it's around 13-14 hours for a complete engine assembly and closer to 19 hours for a long block.

 

Thanks for your help! By the way it is a 97 4.3 ltr rear wheel drive and I'm wanting to replace a long block instead of the entire engine. So I won't be cutting myself short at quoting 20 hrs. That's good to know because I don't want to overcharge the lady nor do I want to sell my work short. I appreciate your response!

 

Happy to help!