Great thread, as I am in the same boat. I am going to put a 360 in my 77 Aspen which has the original 318. I am retiring in a couple of months so this is my "retirement" project, LOL The 318 runs perfect but I want a 360. My Aspen has a 904 and a 8 1/4 with 2.94 open diff. I have two 360 blocks, one out of a Lil Red Express along with the 727 that came on it and a short block that came out of a 83 Motorhome with 12K on it.
Neither block is better than the other. A 360 block is a 360 block; the old wives' tale about early ('71-'73) blocks using the 340 water jacket cores, giving them thicker cylinders, is total bunk. The higher-mileage block would technically be a more-stable platform due to heat cycling, but a 12K-mile block won't even have ring ridge and should be able to be built with standard-bore pistons after a quick hone to renew the crosshatch. It's win-win, really. Neither block is a bad choice; personally I'd probably use the low-mile virgin.
I too am going to use the 904 as it has less rotating weight...
Good call on the 904, but have it rebuilt with cast-iron bands and Alto Red Eagle clutches. Put a shift kit in it, lose the accumulator spring and loosen the line-pressure adjustment until only about 1.5-2 threads are showing on the back side of the plate. Use Type F or FA fluid
only. It will live a long and happy life this way, and give you a screech into 2nd on full-throttle upshifts.
I know I will either have to get a 904 converter with weights or use the B&M flexplate. I am a bit confused if I use the flexplate, does that mean I can use my 318 converter?
Use a B&M flexplate and you can use the stock 318 converter. However, to get the most out of your engine build you'll want something with more stall. How much? Well, that's going to depend on your engine build, but it's safe to say 2,400RPM would be
minimum based on the fact that you mention worked J heads.
I also thought that the pass side mount is different, so I need to find one of those either the right or left whichever one is different.
Driver's side only. It's the same mount used on any 360-powered car with spool-type mounts ('73-'79 B-body, '79-'80 R-body, and any F/M/J '76-'80). It's narrower than the 318 mount.
I also need a pan as both my 360's are truck/van pans.
Summit sells an inexpensive center-sump pan that's a stock replacement. It's a good-quality piece. Any parts store should be able to get you the appropriate pickup; just order one for your car as if it were a factory 360 and you're good to go.
I am trying to figure out which pistons and cam to use also. I am getting a pair of reworked 360 J heads sometime this week, not sure of the casting numbers.
Pistons are going to depend on the compression you want and where your heads measure for chamber volume. I've seen the 3418915 J heads (casting numbers may end with a letter, like 3418915D, etc.--makes no difference) with chambers ranging from 70-76cc so it's best to measure (cc) them before deciding on a piston. A few cubic centimeters can make a big difference in compression. 9.5:1 is a very happy ratio on 91-octane pump junk. If you're not willing to pay for premium, I'd say stay around 9.0:1 which should keep you safe when you get some of that really-bad reformulated crap that passes for gasoline these days. The 916Js are great heads, even with the 1.88" intake valves.
Once you know what compression you're going to have,
call a cam manufacturer. Tell them what you've got, and what you want it to do. Answer their questions honestly and don't try to make it sound like you've got better stuff than you really do.
Follow their recommendations. They offer this service for free and they're almost never wrong. Bigger isn't better, and these guys live, eat, and breathe cams. Cams pay their bills. Don't second guess them. If you are 100% honest with them about what you have and what you want, you will be 100% happy with the cam they choose, guaranteed. If you prefer Comp or Crane or Howard's or Cam Motion, it makes no difference. None of 'em are going to steer you wrong.
Call--don't fill out a form or e-mail. Get a voice on the phone. If they don't want to talk about it, take your business to someone who does.
I will probably start a new thread and see where it goes. Sounds like a lot of gurus here to help us out
Kim
Nobody here but us chickens.
