Wich is the better performance spark plug for a 454 mag EFI the AC Delco MR43T or the MR43TS. The MR43T is a standard nose plug and TS is a projectid tip. Please help. Also is the NGK V power a good performance plug.

Thanks Bill

Donzi22zx....One other plug you might want to try (which is like the MR43T) is the NGK-BR6FS. I've just put a set in on one of the engines (just by chance the place didnt have the others), and, I must say the NGK's are pretty darn good so far. I do not remember the motors starting up quite that fast before.


Bob

Donzi

The MR43TS is definitely the performance plug to use. The farther you can get the tip of the spark plug into the combustion chamber the better. I've been using these plugs for 2 years now with no problems.

Bo

I run the NGK R5673-9, stock #3442. My engine is a blown 509, 878 horsepower. Just ordered a new set from Summit.

Craig

Try an A/C Rapdi fire plug,,, part # 1

What is the difference between the MR43ts and the R43ts? I'm sure M stands for marine but what exactly is the production difference?
Ken

try the ngk race plugs i think the number for you to try would be r5674-7, i have used them for years. they really work well and are very reasonable in price under 2 bucks from lane automotive (motor state distributing) in michigan

The M does stand for marine. Both plugs perform exactly the same but the marine version, which is always more expensive, has a rust proof metal case. I use the R43TS plugs and change them every year and don't have a problem with them rusting. I guess if you change plugs every 2 or 3 years you might want to use the marine plugs. It's no fun trying to get a broken plug out of a head. Sometimes the cylinder head has to be removed to do it.

Bo knows