So I'm tweaking, tuning, learning things as I go. I'm working with a Road Demon 525, Accel HEI distri, 305 with a 700R4 trans. (Yes the carb seems a bit much for the car and I plan to test a lower CFM carb against it later.) Its got the whole air cleaner header and exhaust job to breath. A port and polish job on the intake manifold and heads for better flow. Timing is only 5 % advanced for this testing run.

The last test run was great from 0 to 90mph. I was manually shifting the automatic through the lower gears keeping it in 1st till a good shiftpoint, 2nt seems to take over and **** through the gears by itself at that point. For what the engine is, it ran great. The RPM's stayed high around 4k + while pulling well.

Now lets say I'm already going 40 / 50 mph and I want to floor it, have the auto take care of the shifting while getting the same pull that I got from the 1st run. I can get out of over drive, give a split second for the trans to catch then floor it. It will sometimes do well, you feel the downshift and rpms go up to 4k then climb. Other times the rpms only go to 3k and slowly climb. At that point it just feels like I'm dumping gas into the engine with no response.

I'm wondering if this bad response is because there wasnt enough vacuum to open up the secondaries, not enough air being pulled in to match the gas and produce a decent a/f ratio. If the tv cable is loose or to tight where it fails to respond keeping the car in the wrong gear vs the throttle position. Maybe the timing isn't advancing high enough intime to adjust for the sudden mix of more a/f. Its possible that the engine doesnt creat enough vacuum to run these vacuum accessories. If I have low vacuum due to wear and tear then this could mean the vac advance isn't kicking in at the desired time and the vac secondaries aren't opening with it.

The most I've thought about doing so far is messing with the timing some, trying a different spring in the vac advance to open up at a lower rpm or giving the tv cable a few clicks to loosen or tighten it. So far the tv cable causes shifts in all the right places under normal driving conditions so I'm not too worried about that one first. From all of this info, I'm thinking maybe I just have a vacuum issues. Any thoughts on tuning or small repairs?

If your answer is "Just get a 350" or some other engine lol my reply to you is that yes I will someday. I'm just wondering what I can do to this current engine now.

 

First off, you should get a repair manual if you don't have one already and adjust the TV cable per the instructions in the book, this will eliminate that being part of the problem. Secondly, the vacuum advance, if anything could be leaking, so you can check it by removing the distributor cap and applying a vacuum source to it and watching to see if it is functioning, if not, easy and cheap enough at the local parts house. Running the aftermarket carb, you will need to have the proper brackets for attaching the throttle and TV cables to the carb. I assume you are running the stock intake because you didn't state otherwise, but if not, you will need to make sure the brackets for these cables that mount to the manifold are in the proper position and adjusted correctly. Try these things and see if you don't get some improvement.