I'm in the planning stages to replace my 400 with a 460 and I need to gather some information and suggestions.

So far the plan is to buy a crate engine and build it up at my shop over time (Where I have a forklift and lots of room). When the 460 is ready I'll pull my truck in and swap out the engine. I will replace the clutch and remove the transmission and T case to clean them up and replace the seals. My 400 should last another 10K miles if I baby it so I'm in no hurry and this is not my DD. I should mention when I start the engine swap I will need to be pretty quick because my shop is a place of business and although I might have the room and free reighn I can't have truck parts scattered all over the place.

My questions are,

1. What is a short block 460 Vs. long block?
2. What year should I get? Does it matter?
3. I want to keep my transmission and driveline system so what type of engine mounts do I get? I see some kits at JBG for this type of application.
4. Bell housing clearance issues with my clutch? I hear rumors about this problem.
5. I have never removed a transmission and T case before and it looks heavy. How do I remove them without killing myself? I thought of making a jig to fit on my floor jack.

Anything else I'm missing? Thanks in advance!

 

hmmmmm! I don't know of any clutch/ bellhousing clearance issues, but all my conversions entailed an auto. The motor mounts are a unit you can either purchase or build, the "L&Ls" are a nice fitting mount, but the 4 sets my brother and i had all broke with no luck on the "Lifetime Warranty" I started building them out of 390 4x4 f250 mounts and using 2 bolts in the engine side. Others love L&L mounts. I like my L&L headers though. As far as the engine year, the old high comp. engines would sure get you over the mountain passes in a hurry but my boss hat a 72 ford dually with a 10.5 to 1 lincoln 460 to pull a backhoe, it pulled the backhoe, but there was always a heating issue, a little too much compression to tow, the exhaust just got too hot. It was switched to a ~9:1 or so and the headers stayed way cooler. and the starter was happy too. I would build a 460 RV cam L&L headers, performer rpm intake, holley 4 barrel, straight up cam timing, maybe some minor porting, and stock or slightly above stock comp. The engine years are important. If the engine is pre unleaded (1975 or so) correct me if I'm wrong someone the heads won't last well on unleaded, so a lot of money is invested to obtain proper valves and seats. As far as the tanny, yes they are heavy. I have done this operation with a floor jack but have a few people available to help steady it. I have pulled the transfer case, removed that, then removed the tranny. not a bad way either. Long block has heads, oil pump, timing set, cam, freeze plugs, and sometimes more depending on the engine. short block generally is minus heads, maybe minus cam, oil pump, timing set. Fine if you plan to upgrade these parts. anything wrong i posted or anything i missed, someone please correct me.

 

Short block is a sealed up lower end, Long block, same short block but with heads and intake. If I had a choice I would look for a 69-71 pre smog. I have heard the pre smog heads wont last long ether. They don't have hardened seats but I have a 69 460 stock with c9 heads on it for over 10 years and never had a problem. Also at the advertised 10.5 to 1 and I run cheep 85 octane gas in and never had any problems with it.

 

My brother and I have done a 460 swap on a 79 4wd and an 81 2wd. In the 79 we used the correct balance 460 flywheel and diaphram style pressure plate. There is a difference between the diaphram and borg/beck style clutch disk and they will not work with the other style pressure plate. The borg/beck disk is thicker. Make sure your parts store doesn't mix/match or the clutch will not release (ask me how I know). I also used 1965 352 mounts and enlongated the holes on the mounts to use 2 of the three holes on the 460 block (diagonally). I also had to grind a little on the corners of the mounts to get them to clear the exhaust manifolds. After that the studs from the 352 mounts went right in the holes of the frame horns on my 79 where a 400 once resided. I used 460 truck exhaust manifolds from a later model and was happy with them. The passenger side car manifold hits the frame. Some guys notch the frame to use the car manifold, but that spooked me. Also the correct rear sump truck oil pan. I have seen some guys get by with a front sump car pan if they have some lift to prevent the front differential from hitting the pan when the suspension cycles. As far as the tranny/t-case being heavy, they are WAY heavy. If you got a buddy with a motorcycle jack, they work pretty good in lieu of a tranny jack.