I've recently mocked up my engine before I get the swap done sometime in the next few weeks. I'm running into a clearance issue with just the #3 primary tube.

This is my combo:
Dart Pro 1 heads (angle plug)
Hedman LTs (http://www.summitracing.com/parts/HED-68468/)
Taylor 90 degree boots

Now, NOBODY around here seems to have anything OR just doesn't have the intelligence to look. Either way, I figure SOMEBODY on here has had to have this exact combo given the popularity of the parts, and thus explain to me what they've done to fix the issue.

The research I have done keeps bringing up the Accel 0416s, and before I go and order a set through Summit, I figure I better see if that works given my combo, AND if there are better plugs out there that would fit. I hear that the Accels are junk. I also have heard of people "grinding down" a regular length plug.

And just before I get more questions, I understand that there's 2 factors. What will physically fit, and what my engine would want to have as far as a heat range, resistor, etc. Here's what I got:

Holly Stealth Ram
42lb injectors (E85)
11/1 compression
Maybe every once in a while spray a 150 shot of the squeeze.

Any input is helpful guys. Thanks

 

Why not special order the Accel plugs from local autozone or advance - they'll be there in 24 to 48 hours, free shipping, and hassle free return if they don't fit.

I run an Accel shorty plug due to having dometop pistons (but I have different heads, etc.), and I've had no issues with them at all - they've been in the car for 4 years now with no issues - so not sure why anyone says the Accel plugs are not desireable. I actually just grabbed the whole set off the shelf at Pep Boys I think it was.

Anyway - you should always try local partys stores first - usually cheaper than internet prices, arrives much much faster, and totally hassle-fre returns with no return shipping fees if it's not right. I order everything from local stores for those reasons!

 

I'm confused. What does having domed pistons have to do with running shorter plugs? And from what I've heard, the Accel shorty style U groove plugs, the 414s and 416s, like to foul out. There seems to be a lot of negative things said about them. In fact, you are the first person I've read about that's said anything good about them. As far as the part stores, OReilly's, Advance, Autozone, Napa, etc all say it would take a week to get them in. Summit said 3 days, PLUS I got $20 in Summit Bucks anyway. That's not really what I care about though. I'd pay $100 and wait a week if I could just find a plug that would physically fit and be in the right heat range (4-6).
I've done a little more looking, and people keep bringing up the NGK FR4/5 (FRM-5155). The local store's site says they have some. I think I might go look at them.

 

The "shorty" plug has less threads - thus it literally screws less far into the chamber than a regular plug. Regular plug in my head results in the piston hitting the plug - thus I have to run the shorties. The shorties are not shorter between the hexagon where the socket goes on and the tip where the plug wire connects, they are shorter on the half that is inside the chamber. Or at least the ones I got are.

 

You are talking about the actual thread reach, most of the gasket seat plugs have a .75" long reach. You're talking about the .46" reach plugs that have a tapered seat. A "shorty" designed plug is physically shorter from the seat of the plug to the end where the plug wire attaches. Go to Summit, put "spark plugs" in the search, and look at your options on the left side of the screen.

 

i have to run shorty plugs with both my edelbrock and
SLP headers using taylor 90*boots-found bosch plugs
are shorter and clear the headers and older AC delco
-say '85 and earlier manufacture date-also are shorter
and fit(bought a bunch of NOS'82 vintage delco plugs
at a swap meet years ago,run those in mine)
Never have used accel plugs in my third,but have used
them in my dodge and saab-AFAIK,the accel plugs are
made in japan by nippondenso-i have not had any
trouble with them in those vehicles

 

Thanks for the info. What heads were you using when you were using the Bosch plugs?

 

stock'624 straight plug iron heads.I'll check if i have any
SBC bosch plugs handy,measure the length and post it
here along with any other shorty plugs i have on hand
Ok,grabbed some plugs to measure(taper seat):
from outside edge of taper seat to terminal tip:
-bosch:2.10"
-accel shorty#576s:2"
-'82 vintage ACdelco:2.10"
-later,Ca.post-'85 AC plug:2.30"
-autolite standard:2.30"
-champion:2.30"

 

Sounds like I need to look into some Bosch plugs then. I'm sure finding a set of vintage AC Delco's is going to be tough. Only issue is I need the .75"reach thread and gasket seat.

 

i might have some plugs of that style to check too-i'll
google accel 0416s to get an idea of the plug style and
dimensions.