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Firebirdjones · 12-12-2009, 04:28 PM

The AC plug R44TS is simply the small 5/8 plug with a taper seat and extended tip.
T=taper seat
S=extended tip

GM started using these plugs in both big block and small block chevrolets in 1971 and work in pretty much anything up through the late 80's with a cast iron head that doesn't require more reach.
You can go as cold as 43's which is what I run in a couple of cars, but that heat range is getting harder to find. Seems the 44's are also getting scarce. You can go as high as 46's if you wish.
Most parts stores want to sell you the 45's it seems.

For stock or nearly stock engines and close to sea level, I'd shoot for the 44's and go from there.

As far as the HEI's, they are a cheap alternative to electronic ignition. Very dependable. The downfall is the size for me. I never liked the bulkyness and the amount of crap you have to remove for a simple cap and rotor change.
I'm an MSD person myself, used them for 20 years without a hickup. They can be made to look stock as well, if you are into the stealthy stuff.

But a good setup is 5 times the price unfortunately.

12-12-2009, 04:28 PM	#14
Firebirdjones Registered User Join Date: Oct 2009 Location: Prescott, Arizona Posts: 2,396	Re: HEI dist in 4x4 72 Jimmy/Blazer The AC plug R44TS is simply the small 5/8 plug with a taper seat and extended tip. T=taper seat S=extended tip GM started using these plugs in both big block and small block chevrolets in 1971 and work in pretty much anything up through the late 80's with a cast iron head that doesn't require more reach. You can go as cold as 43's which is what I run in a couple of cars, but that heat range is getting harder to find. Seems the 44's are also getting scarce. You can go as high as 46's if you wish. Most parts stores want to sell you the 45's it seems. For stock or nearly stock engines and close to sea level, I'd shoot for the 44's and go from there. As far as the HEI's, they are a cheap alternative to electronic ignition. Very dependable. The downfall is the size for me. I never liked the bulkyness and the amount of crap you have to remove for a simple cap and rotor change. I'm an MSD person myself, used them for 20 years without a hickup. They can be made to look stock as well, if you are into the stealthy stuff. But a good setup is 5 times the price unfortunately.