[1971-Chevelle]

I am having a very difficult time deciding on whether or not to get short spark plugs. People on other forums do not like the Accel ones - they say they have performance problems. Autolite does not make a .750 reach gasketed version. I think that NGK does, but they are like $42 EACH (no, thank you).

I found these from MSD and was wondering if anyone has tried them - Click Here I guess I could start looking into getting headers that fit better (I am running the FlowTech 11100 headers now). The clearance is very tight on numbers 4, 6, & 5. I have fiberglass boot protectors on those, but they actually touch the header tubes a little bit.

If anyone has any ideas, your input is greatly appreciated. Thanks in advance.

 

[bowtie0069]

Do you have angle plug heads? What plugs are you currently using?

 

[1971-Chevelle]

My heads are straight plug. I am currently running the NGK 5632 (equivalent to the Autolite 3923). I didn't really have any clearance problems with the Procomp heads, as they were machined wrong, so the plugs were recessed into the heads about 1/2". The Dart heads are machined correctly, so the plugs are out further towards the header tubes.

 

[THAT1GUY]

Bump...I just picked up an accel 0416s and it cant be anymore than 1/16" shorter than my autolite 3924 plugs. I keep hearing that these accel plugs are the shortest for aluminum heads but it seems like there has to be something better out there.

 

[Tom Mobley]

those 3924 are pretty short. sort of the standard plug for aluminum heads and headers. If your headers won't clear those, they're not made right.

 

[68Cpe307]

I been running accel shorties on my stock 307 for ten years and a mild 350 for five years with no issues. perhaps they are not good enough for a performance engine but I've had no issues. they are pricey but do help out a lot on the inner cylinders (4,6 and 3,5) header clearance.

 

[1967 chevelle malibu]

I have the accel 9199 taper seat on my 67 Malibu with 350 engine, they fit fine with my Headman headers & performance is the same as AC Delco plugs replaced when headers installed.

 

[mrpaticular]

I use Accel 276S - 355, bowtie angle plug heads, headman headers, msd wires with 45* boots.
I go through 1 set of plugs a summer. Wires have clearance and don't burn.
The only thing about these is you need a back up set just in case there is a fuel problem. You typically have to order them.