Engine swap questions

Hey everybody recently my friend swapped my 89' 305 with a 350 from a van I bought from a guy with a tow company. I can't recall the exact casting number but I know the year range was 86 or 88-94. My question is now that it's in my caprice how do I approach buying parts for it? Do I treat my car as a 89 caprice with a 350 or should I look for parts for a van of that year range? My thinking is its basically the same engine that would be in a caprice but of course if I'm asking I'm not sure.

My major concern is tune up items. Also I have like 4 oil filters sitting around that went to my 305 and I see they could go on a 350 too just wondering if they should be sold or given away or if I could use them. The filter that was on the 350 was a Mobil 1 M1-302 which is considerably larger than the filters purchased for the 305. Distributor cap, rotor and all that seem to be the same. Different numbers on wires and spark plugs but some plugs show up for 305, 350 and 350 vans.

So confused yet don't even know if it would even matter lol.

The only difference between a 305 and 350 is the diameter of the pistons. Everything for that 305 will work on a 350 and vice versa. The only things you would want to keep for each specific engine are the fuel injectors and the knock sensor/module.

The only difference between a 305 and 350 is the diameter of the pistons. Everything for that 305 will work on a 350 and vice versa. The only things you would want to keep for each specific engine are the fuel injectors and the knock sensor/module.Ah, thanks for the quick response as always Silicon. Would having the fuel injectors from the 305 on the 350 explain the problem i'm having which I could only describe as feeling like the engine flooding when I had my other 88 305 that had a carb? Basically it feels like the car starts to stutter or "putt" then a surge of power sometimes the stutter is so bad the car may stall or there may be a backfiring.

Also what does the knock sensor do?

The 305 injectors may not deliver enough fuel for the 350. The knock sensor is a part of the Electronic Spark Control subsystem of the OBD system - it bolts onto the block on the passenger side, in place of the water jacket drain (just above the pan rail in the middle of the block). The ESC module is bolted to a bracket mounted on the passenger inner fender. It's a large square thing (about 2'5" square), with a 5-lead connector. One lead goes to the knock sensor. The purpose is to retard the ignition timing a couple of degrees when detonation is detected (the 'knock'). Using this setup, the timing can be set more agressively overall. This helps to lower tailpipe emissions, while at the same time increasing average engine power.