Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Yeah, I read through that thread and think he's nuts lol. Trust me, I get what you're saying. But for the effort it takes to get it there and source the parts, especially when you're talking a lowly 305, it's not worth the hassle IMO. Better to just stab a regular distributor in, set it and go.
You've put it on the 75 C20 in your avatar?
I have several trucks,that ones getting a 6.2. Yea I know those suck too. But it suits my needs,pull trailers and get reasonable milage.
Yea I never said a stock HEI didn't run good I,'ve run lots of them. I even told the O.P. in post like 12 or 13 he's already changed it. It's not worth changing back. HEI and an ESC HEI are the same distributor,with the exception of the module and pigtail.Weights,springs,pickup coil,vacuum can etc. all interchange. To make a ESC distributor non esc all you have to do is splice wire a to wire c. I personally think having the ability to run more timing is an advantage. But I never said a regular HEI sucks. I also said around post 15 I don't want to argue about why I think ESC is better. But because some people wanted to know. I went there. I regret responding now.Old doesn't mean bad, new doesn't mean good. Mine and countless others run great without it. High compression and all. We agree to disagree.
You are equating HEI=ESC... that is not the case. HEI came in all squarebodies from 1975 on. ESC was ONLY on LE9 engines(305). The timing control that came into the TBI, TPI, and later EFI systems is very different than the dumb knock retard only ESC that was in the LE9 used in the trucks. It is an especially terrible and unreliable system between the type of sensor used, the location it was installed, and the computer that was reading the signal.
Oh yeah GM had dozens if not 100s of combinations of weights,springs,center cams,and advance cannister. I've done more than my share of recurving GM HEIs. I don't want want to beat on this anymore,Personally I like the ESC especially if the distributors are curved the same. That or a putting a D1941 5 wire module in a 4 wire HEI, that,allows you to pull 5* on demand like going up a long hill pulling a trailer it's not fancy or complicated just does what I like. The D1941 is not the 5 wire truck ignition module.
My whole thing with this is that he DOES NOT HAVE A 305 anymore. I'm betting that when someone swapped the engine out, they likely didn't transfer over the knock sensor either. A properly built 350 with no mechanical issues should have no issues with detonation; even hot, heavily loaded, or on pretty bad gas. My 350 got flat tops, .020" off the deck to bring the quench area in check, and a small towing cam to bring my compression up near 9.5:1 and bring the quench area into a reasonable range. I've towed a 6k lb camper through the mountains in 100 degree heat on 87 octane and had zero issues, but I also have a properly tuned quadrajet and am running 12 degrees of base timing, 22 mechanical, and ~9 vacuum. So, full throttle it is peaking around 34 degrees and cruising at highway speeds it can hit over 40 degrees.
So using your numbers 12+22+9 you've got 43 degrees on the highway, but you'd get better milage,even without a different carb running 50 degrees on the highway. As to whether or not 350s had Knock sensors,they did Corvettes in the early 80s,Cali. Spec trucks 83 or so,TBI trucks,Vortec trucks,I don't care how crude the system is compared to a new system,everything on these trucks is crude compared to newer stuff. A th350c is not near as good as a 4l80e,but I wouldn't pull a good th350c to put in a regular th350 with logic of the th350c is crude compared to a4l80e. I woukd replace a 350 with a th350c thou.HEI is crude compared to 87 up stuff. As to whether or not O.Ps ESC worked IDK, if I swapped in a 350 and the option of having functional ESC was there by adding 1 sensor,I'd have working ESC. A knock sensor HEI,is everything a regular HEI is with the ability to pull timing,not only pull it,but give it back when you can use it. People have no problem permanently pulling 2 degrees of initial and 4 degrees of vacuum and never getting it back. I want it back. People want to bag on @SirRobyn0 spending time and money making his ESC work (yes I know its a 305) but the couple hundred bucks he spent,made his truck more useful,more drivable and gave him more mpg. his mpg increase will pay for his repair,so it was worth doing. I have different goals for my trucks the aren't pampered,they aren't pretty,I don't care how fast they are, I do want the best mpg without hurting the vehicles intended purpose. Haul things I can't in a car ,and pull a trailer when I need too.A knock sensor HEI can be tuned and tailored EXACTLY like a regular HEI but a knock sensor HEI can do something a regular HEI can't. Pull timing if and when needed. I can have my cake and eat it too. I can pull 50 degrees on the highway,I don't need to limit my vacuum advance. IDC if the crude system was designed for a 305 it still does the intended job. If you aren't running 50 degrees on the highway,you are leaving milage on the table. I'd rather have too much,money,gasoline,tools,or timing and not use it all, than be just a little bit short.This is why I didn't want to get this ball rolling. My Chevelle will have 305 ESC on it,already gathered the pieces.
You are making some broad generalities there that are not necessarily true.
