Im looking to get a 302 / 342 crate engine from Ford Racing and swap it into 87-89 lx 4-cylinder... im hoping the 5spds are the same from each car (the v4 and the v8) but what else am I going to need to get / replace ??
Not to be a d*ck but that isn't a V4 its an inline 4. you get the V when you have equal numbers of cylinders on each side of a block (making a V).
The t-5's have differences between the 4 cyl. and the 8 cyl. Someone else can tell you exactly what those are and that should help determine what you will do.
The severity of the conversion depends on a few factors. Is this a strip only car? Street car? How big is your budget? The 4 cyl manual transmission will not hold up to the 400 ft lbs of torque that the 342 makes. Brakes are a pretty big issue with the 4 banger cars, They just don't brake well, end of story. So you may have want to upgrade those. The 7.5" rear will blow, so an 8.8 inch will have to replace it.
The suspension will need some attention as well. Many guys use the 4 cyl springs up front for weight transfer, but the rears need to be upgraded.
Assuming you go with a crate engine with a carburator, you will also need a carburator fuel pump. The Fuel injection pumps are too powerful.
Lastly, I believe the 4 cyl driveshafts are shorter as well, though I'm not certain.
There are many other things that I am leaving out, but those are the main things.
There is a lot of work involved with this project. I researched this, thinking I was going to go this route. But it was too much for me to handle at that time. If you do go ahead with this, all the luck to you.