You forgot to ask how to get the old glas out!

(Hint: "piano wire")

BTW, pull off as much of the olk caulk as you can using an old rag. Remove the rest of the residue using a plastic scraper and WD-40......

I didn't do the newer style windshield because mine was a do-without project based upon the notion even a poor person with some knowledge and fortitude can have transportation. So, anything that could be removed, cleaned up fixed, adjusted and made to work was included. $17 for moulding clips and $40 for salvage yard glass was far cheaper than new 91+ glass and gasket.

the urethane thickness is an issue. For starters, you need to use what's known as a "high volume" type. this is contrasted with the "flowable" type used for resealing a leaking window. The high volume is a thicker consistancy and tends to "stand" up. Think of what you are trying to do -- replace the ribbon of buytl-rubber caulk that was installed at the factory. It had dimension to it.

Because I didn't know how I would achieve the stand off depth I needed with my 3M Windowweld Urethane, I decided to also use the buytl-rubber rope to achieve this. The urethane asured added sealing and some structural integrity. (Urethane glued windshields are considered into the safety of the vehicle, I found out)

Unless my old 240 was some sort of show car, I don't believe I'd stress too much over switching to the newer glass & gasket just to reduce wind noise or to stave off fear of future leaks. (The buytl-rubber used to dry out over 15 years, while the urethane will not).

I have done two cargo windows in a 245 and found that experience less satisfying than the straightforward placement of the glue in and trim windshield.

With the gasket style, you place a bead of sealant unside the "track" of the casket, lay in a nylon string, lift the assembly onto the bottom ledge of the body opening then use the string to pull one wall (side) of the "track" of the gasket over the pinchweld all 'round.

I found it messy and things didn't seal right in either attempt. I later needed to buy and inject flowable silicone under the gasket to seal everything.

Abd that was with reasonably good access to the glass, unlike the bottom edge of a windshield where the angle limits you.

Another tip: Tape down some masking paper to the dashboard to keed the urethane off of it and eliminate a frustrating clean up job. I but a 16" wide roll of that stuff from Home Depot and keep it in my shop for all sorts of small painting jobs.
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'Most Improved Patroller of the Year' Blue Mountain Ski Patrol, Palmerton, PA