tilt&trim on 90 johnson

I got a question about adding tilt and trim from a junked 90 Johnson to my 9o Johnson I got to replace a 75hp Johnson(Model75ELR76D ser.J4550974) that lost the lower unit Both the 90 hp Johnson's are early 80,s (sorry I don't have model number with me I just dropped motor off at the shop .I was just wondering if that could be done or is it just not worth the trouble.. My 75 did not have t/trim either but it would probably make a bigger difference with the added hp. The boat is a 17.5 fish and ski.Hoping to luck up a find a used gearcase for the 75 as it was a real sweet running motor and had just been redone a couple of seasons back! If anyone had tried this or if not possible any ideas would be appreciated