basically the story goes...i have been doing a rather lengthy rebuild/buildup on my 1984 K5 blazer. It was pretty much my first shot of anything this big (I mostly did very minor mechanic work myself before this project). I got the truck, used off a some guy in new hampshire that pulled a 350 out of a camaro I believe, and ripped out all the non-essentials (like A/C), along with gave it a 9" lift (6" suspension, 3" body). The engine seemed kinda tired, and started having oil pressure problems, so i decided that was a good enough reason to rebuild the engine (since I wanted to know how).
Pretty much following the plans/instructions out of a couple of magazines and books, I tore down the engine, threw out everything but the block, brought it to a machine shop, had it cleaned, checked for cracks, then they bored it 60 over (apparantly it was already rebored once). then I got a 383 stroker kit, KB hypereutectic pistons, vortec heads, edelbrock performer vortec intake, and then an edelbrock 795cfm q-jet carb. I don't remember the details off the top of my head about the camshaft I got, but it was profiled more as a towing/low-rpm cam. I got it from crane cams. I also decided instead of going with a timing chain, to get a pete jackson gear drive system instead. I had a friend verify that I degreed the cam correctly, and that the timing was set at what we though was the right number. The distributor is a accel HEI setup...nothing too special.
I figured it would be good to get some background on the engine. But as far as what you asked about the headers and spark plugs. not long before I decided to do the engine rebuild, I had a flowmaster exhaust put on by a custom exhaust shop that did a pretty lowsy job in my opinion. For example, when I left the shop, every once in a while the exhaust pipe would smack into the spinning driveshaft, but in any event, around the same time, the catalytic converters (the only thing I didnt get replaced during the exhaust install) somehow went bad, and clogged up and started glowing red. I brought it back to the shop and they replaced both converters.
So...in theory I had a 2 year old exhaust system from the headers back. the truck definately has headers, but they are the original ones that came with the truck when I bought it. They have a nice coating of rust over them, and I have no idea what make they are.
I did have plans to replace the whole exaust system from the engine back because I wanted new headers that i knew matched my new engine configuration, and also I hate the exhaust job the shop did, and I am not confident about how they replaced the catalytic converters. So if everyone thinks that the problem is most likely the exhaust, I could just escalate that. I still have a long laundry list of items to buy for the truck, so its been kind of a triage type thing trying to decide what takes precedence.
Also, you mentioned in your situation the smog pump what partly the culprit. I didn't hook up any EGR stuff, so that shouldn't be an issue.
I replaced all the gauges with autometer gauges, as far as oil pressure goes, I am pretty sure when I started it this weekend (I live in Massachusetts, so its still a bit cold) the oil presure was up around 60 I believe, and the engine (well, at least from what the temp guage is measuring) didn't even have time to warm up before the header started to glow. The truck does run rough, and it still seems to have some trouble idling on its own without me giving it some gas. I think it tries idling somewhere around 500rpms (which seems low to me).
also, the spark plugs I am using are bosch platinum+4's and the wires are the normal bosch wire set.
As far as your other ideas go, my first guess about why the engine was running a little rough was because the fuel mixture and maybe the idle speed needed to be adjusted some.
I could also see there being some form of a manifold leak due to a bit of an accident I had while installing the manifold. Somehow, while using a torque wrench I snapped one of the grade 8 bolts I was using to bolt down the intake (it was the last bolt on the back right of the manifold). It was strange that it broke in the first place since i was using a torque wrench set to 35ft-lbs. (I tested the torque wrench to see if it was broken, and it was fine). But when the bolt broke, it cracked the very corner of the manifold. I used JB weld to stick it back together in hopes I wouldn't have to buy a new manifold, but I havn't seen any coolant leaks (there is a coolant passge right near the crack).
So the other idea I was thinking of doing was testing the manifold for vacuum leaks or whatever. I have a vacuum gauge (and a compression one, although i am not sure a compression test would help at all for this) but I am not exactly sure how to correctly test the manifold vacuum.
I know I rambled on quite a bit, but my gut is telling me tha the problem is the exhaust, because it seems like if it was anything else, both headers would be overheating, instead of just the left side, and if the manifold crack wasn't sufficiently repaired, I feel like either coolant would be leaking, or other things would be happening on the right side of the engine instead of the left.
any opinions?
