I have recently upgraded my FT360 to FT425 W/AWIC and am going to install better connecting rod bearings. My question is, can this be done with engine in the car? If so, is there a DIY guide to use?
I don't have a DIY but sometimes it more fun to pull the engine and do it, it may even be easier and you can upgrade other things at the same time to include timing belts and what not.
Anyway you just drain the oil and coolant, remove the oil pan, then remove the intake manifold, then the valve cover and timing chain covers, to get to the head bolts and timing chains. Don't forget to rotate the engine to TDC before removing the head to make it easier to ensure the timing is set on the re-install.
You can go ahead and break the torque on the connecting rods (from under the car) and remove the rod bolts only. (don't break the torque on the main cap bolts).
Once you got the bolts out of one rod you can use the handle end of a mallet or hammer and lightly tap up on the bottom of the connecting rod until the piston clears the top of the block and you can then Pull the piston out of the top of the block and prep it for the new bearings.
Ensure you use lube as necessary so nothing gets bound up.
If you have pre fit bearing and want to save on time you could just remove the oil pan and acsess the rods from the bottom without removing the head and install the bearings from there just double check everything prior to torquing anything down and ensure the bearings are installed flush with plenty of lube.
Good luck with it.