My brother in law has an '87 or '89 YJ with a 4 cylinder motor. I don't know much about the YJ's so I'm dumb on this one...

He wants to get new springs...actually he wants to lift it. Origionally he wanted to go with 33's. I think that I talked him out of it. He doesn't want to spend the $$ to change gears and his motor isn't real healthy. I Think he has stock springs and 30x9.5's on it now but they are bald.

Realistically, what can he fit and still have it driveable? What springs would you go for?

I told him that he didn't want to go over 32's, but in my mind...31's are probably the limit...how wrong am I???

...any help and/or suggestions would be appreciated. and thanks in advance...

We need more info. What are the future plans with the Jeep. Engine swap, rebuild current engine, Fuel injection. As for now with a weak 4 banger i'd say 31's. The upside of all this is he should have 4:10 gears in the axles. This way after he upgrades the engine he can run 33's on a 4in lift with no futher mods. Just needs more power.
On the other end of the scale A buddy of mine is running 38's on a fuel injected 4 cyl YJ with 5:38 gears. Not very often in 5th gear but it gets the job done.

I have some 31x12.5 thornbirds for sale if here would like new tires.

i have a 95 yj,4 cyl, has only a 3" body lift, and 35's
not a good idea ,about as slow as a herd of turtles stampeding through peanut butter,cant use 5th, can barely use 4th,crawls well though,