Jer82Z28

What spark plugs and gap are your vortec guys running in your carb/HEI cars?
I've went through 2 sets of plantnium plugs while running .65 gap per the recomended gap for Vortec 5.7's

I was told I cannot run non plantnium plugs because they will melt, but he doesn't know I'm running HEI. Is it because of the electronic ignition that the recomended gap is so big?
but I also heard taht HEI don't like plantium plugs.

i recently purchased NGK Tr55's and got maybe 100 miles on them and it started backfiring like crazy, my other platnium set lasted me 1000 miles.

Ray87Z

I've been running Bosch Platinums, part number 4205 in mine. You sure you're getting the right plugs for the Vortecs? I've been gapping mine at about .50 though, I didn't realize the specs called for .65...

I have not had any problems w/ the plugs lasting though. Several thousand miles on the last set I just pulled out a week or two ago and they looked fine.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

zippy

try some ac plugs. three options. 41-932 for platinum, R44LTS for standard, and #8 for rapidfires. gap .060 for platinum, .045 for standard, or .035 for rapidfires.

SCRA rules!

I'm doing the same as Ray87Z-gapped about .050. 4205 is just the box #-the plug # itself is HR8DPX. This is a stock replacement plug for like a '97 pickup with 350. Make sure your plugs have 3/4" of thread also. I have had very good luck with these Bosch Platinums. Another bonus is they are just as short as the Accel shorty plugs for the regular heads. The Bosch's are the only ones that would work with my Thorley headers. The headers were on my original 350 and never had probs, but since the vortec exhaust port is .100" higher, this raised my header to where the #5 boot kept burning. Bosch's gave me just the extra clearance I needed.

------------------
'93 2wd truck
408 sb, vortecs, 454 TBI, Comp Cam, dual exhaust

Ed Maher

Your problem isn't your plugs, it's that mondo plug gap. Your ignition cannot support a .065" gap. Even with an CD box i wouldn't try to run a gap that big. Maybe the vortec trucks run a gap that big, but you are not driving a vortec truck, you do not have the vortec intake/computer running your calibrations, nor do you have the vortec ignition firing your plugs. Heads do not dictate plug gap, the aforementioned factors do.
I can't believe you people are debating plug types when the problem is staring you in the face like this.
And whoever told you that non-platinum plugs will melt should stop breathing as he is wasting valuable air for those of us who didn't eat paint chips as a child.
...ed

Matt87GTA

Man Ed, I was reading all this and I was gonna reply, but you just hit the nail on the head. Pretty f'in funny stuff at the end there too...........................damn, I'm still chucklin'........................

'Jones82TransAM

I know this thread is ancient, but as I am contemplating a 350 vortec engine and heads with shorty headers I thought I had better do some research. There are some differences with the exhaust port on vortec heads I wasn't aware of and this is how they dealt with it:

http://www.superchevy.com/how-to/678...cam-355-build/

InfernalVortex

iTrader: (4)

You had to bump a 13 year old thread for that? Anyway the differences are minor. I think it's more of a pain in the butt from a changing spark plugs point of view than a parts selection point of view. You just need to make sure you get the plugs with the longer reach and then get one of those thru-socket sets so you can get to them easily.

'Jones82TransAM

What you say is fair enough but I searched the issue and this thread came up. I thought that someone else without previous experience like myself may benefit from some findings. You are right this may be a minor issue, but I hope you agree that anything is worth knowing about when sinking thousands of hard earned dineros into a new engine build. I want to know any potential issue that can arise so I can hopefully pre empt it, however minor it may be.