What spark plugs people running g these days. I'm currently on 071's but want to upgrade. Graham Goode recommend AGPR902P's so I've order a set but then i read a newer thread that states these are not made to the same spec anymore (non platinum).

So not sure whether to bother with them or not?

Cars running stage 3

 

If you want to change the 071s then Denso IK27s would be my choice.

You could always try the 902s that you've ordered. GGR do state that they are suitable for high bhp.

 

I have a Stage 3 YB over here in California,
I have tried all the recommended plugs, but found either they don't work well at high boost, 15psi plus, or work well for a short time, like 3,000 or so miles then need re-gapping or are toasted.
I found the Autolite equivalent of the 071's and it works just as good, but is nickel plated and has a solid electrode, so no losing the tip in the boot.
They are Autolite AR3932, AR3933 etc.
There is even a better version made for racing that lasts much longer and never needs re-gapping AR3932X, look them up on eBay, I have a set currently with 15k miles and still working like a new set of 071's

Ps. The Autolite's are much less expensive and made to a better quality level, I have had not one bad plug yet!

 

I had 071's in mine and it miss fired right up the top end, even with a brand new "group a" coil

i never have a issue with IK27's (although mine isnt as high spec as yours) id defiantly recommend them

 

I have tried the IK27's but they are expensive and don't handle high boost as well as the Autolite Racing AR3932 or AR3932X.

 

The AR3932 look like taper seat plugsto me. The AR3933 do look to be the correct heat range though for a Stage 3.

I ran my stage 3 on IK27s for thousands of miles without an issue until they eventually wore out.

 

I always ran ik27'S without a problem

 

no problem with 071s for me

 

Same here but they don't lAst more than 3000 miles in mine. At least the car lets me know by misfiring when she wants a plug change :-(

 

Ik31 on mine with 36psi peak.....

Trouble is when you just move ya car or a sheady puts it shunt it about.
The plugs will foul up quicker.

Ik27 is a good choice or the cheaper ngk bp9exi which i have and will try at some point.

 

Ik27's for me, hard to get a good set of 071's now.