Rams horn and hei questions

['72customdeluxe]

Are the outlets on the slanted 2wd ram horns 2" or 2.25". As much as I like the overall torque and mileage with my setup, I just can't seem to get around the manifold outlet size in my head. Right now I have the manifolds going into 2.25" downpipes that have been severely clearance dented. Then stepped up to two 2.5" Flow 40's dumped behind the cab which will be going bye bye. So anything is an upgrade even if I keep the manifolds. I hate the no crossover sound too. My plan is to either replaced the driver manifold only (cracked when I had to plug up the air injection holes) or get some Hooker headers. Either way, the two initial pipes will be 2.25", then into a 3" single Flowmaster y/merge pipe and into an Xr-1 and out before the left rear tire. I'm afraid of loosing torque with headers as that is all my motor really has and I love it. It's also part of why i'm going to be running a short mildly sized pipe single system (other than being cheap ). Another concern: my ignition consists of a super coil, accel performance module, accel wires, msd cap and rotor. After I got the carb rebuilt and jetted, it still seemed doggy off of the bottom for a light truck with 300 or so lb/ft of torque. So I added 4 degrees timing yesterday, bringing it to 16 degrees initial. Yes, the vacuum advance was plugged and it was at about 600rpm. Today i'm playing with it some more and now have 20 degrees initial. I've heard some of these low comp. smog dog motors like timing, but dang.. Maybe the timing marker is off a little. 170psi compression across the board on 87 octane. Not a rattle or sound under any load with 20 degrees in the heat with and without a/c and full throttle. This has the stock hei mech advance. I've heard those curves are pretty lazy, not giving max advance until too late. Could this be why she likes so much timing? The mech weights do move freely. She runs beautifully and smoother than ever now with the timing change. Sounds throatier too. I think i'm going to play with a mech advance kit. Sucker RUNS now!

[mclairmo]

I believe slanted are 2 inch but the new Corvette ones that Dorman's sells are 2.5 inch but dump straight down. Should clear crossmember fine. Headers should work fine as long as primaries are small diameter. I would confirm balancer has not slipped and then put a timing tape on it and verify when all the mech adv is in. Should be all in by 3,000 rpms or even less. If not, put lighter springs in it.

['72customdeluxe]

Yeah, my inner fender emissions sticker along with my service manual recommend 8 degrees initial but that's points and completely different. Might be for emissions too and my truck has a good number of changes and no more egr/air. I think the balancer might be off

[mclairmo]

Also, remember that stock distributor curves have too much centrifugal advance built into the distributor. You can buy a limiter bushing from MSD to reduce the amount of centrifugal advance. Small block Chevys like about 10 to 11 degrees total advance in the distributor (20 to 22 as read on the crank), with 16 degrees initial timing at the balancer (for 38 degrees max crankshaft advance). I would run 92 octane, too. The centrifugal advance curve should start around 1,100-1,200 rpm and be all in by 3,000-3,500 rpm. Vacuum advance is good for the street, as it promotes improved part-throttle fuel economy and driveability. Because the vacuum advance doesn't function under wide-open-throttle, you don't lose anything by leaving it hooked up. Tune with it plugged and after you get it running perfectly, hook up the vacuum advance and see if it pings. If so, adjust it so you have less vacuum advance. Buy an adjustable one if need be. MSD website has lots of good info.

['72customdeluxe]

So the 2wd slaqnted rams are in fact 2" outlet? Does anyone know?