OK now on to Plan D 1986 Bonneville GS

[Fast355]

I built an Edelbrock 1406 as well in the last couple of weeks and jetted it up enough to feed the 383. It ran for 7 minutes and 24 seconds with the last 20 seconds or so on one float bowl and on 4 cylinders. Well dialed in Q-Jet definately has better low-load fuel consumption numbers. The quadrajet had 15% longer run time on the same exact fuel volume and ran on all 8 until it stalled, something the Edelbrock did not do. That being said both carbs have great throttle response and idle manners and are seamless in throttle transitions. A couple of throttle rips on the primaries had it up to 6,000-6,200 nearly instantly.

HEI was setup to give 15° centrifical mechanical advance by playing with the center plate and weights. With medium springs from a mr gasket recurve kit, 363 center plate and 053 weights, timing curve started at 1,500 rpm and reached full advance by 3,600. Initial timing set at 16° BTDC. WOT timing is 31° @ 3,600. Vacuum advance is connected to manifold vacuum, canister starts advancing about 7 in/hg and fully in by 12°. Vacuum advance has a hei weight bushing from the mr gasket curve kit slid over the shaft into the guide channel. Limited it about 2°. Total timing at 3,600 rpm with the vacuum advance connected was 46° btdc. Idles at 650 rpm with a stable 31° of timing and nearly 18 in/hg showing on the gauge. Cam is 218/228 on a 108 LSA and 104 ICL. 0.578 lift with the 1.7 rockers. Rhoads V-Max lifters adjusted cold to the bottom of their travel with a 0.014" feeler gauge between the valve tip and rocker arm. The lifters and rockers are a little noisy but run fantastically. The rhoads lifters really tame the idle and low speed manners of the tight LSA cam.

I did the Q-Jet fuel consumption test with and without 2 chambered 40 series flowmaster knock off "rumble" mufflers. The rumble mufflers added nearly 30 seconds of run time to the q-jet and dropped off about 1 in/hg at 2,000 rpm. RPM stayed the same. I believe the mufflers kept the tri-y headers from over scavenging the chambers, allowing for some internal egr.