Forged pistons are justified when cast pistons will no longer hold up & i can't see that happening in a normally aspirated street engine.

I ran my 1200GX engine for a lotta years & i think i could count on one hand the number of times that it ran past 6,000. I never needed to

Hyperutactic pistons are fine. They are better for the street as they take less time to warm up. Casties all the way for a race motor

Cast pistons won't be a problem. Im sure alot of others will verify this. Fully balanced it will rev pretty high safely.

ang94541

You have a good question there.

I am about to take my GX engine out at the end of the year and fully rebuild it with a balance and some 40mm sidedrafts.
If that is the case of revving too hard pistons will get damaged, I think I will keep my engine stock as here in South Africa we do not have places that make Forged pistons for our cars. I also do not want to spend a arm and a leg on Forgies.

How long do stock cast pistons last at 7000+?
I've always thought they fall apart after a while if reved past 6500, anything above 6500 on a regular basis would require forged.

yeh my a12 used to pull to 8k then it was enough next gear, that was with a huge cam (280) 36 webber and 2inch exhuast. my 1400 only pulls to 7200 with a milder cam(270) head work extractors and a 38 webber, but does 160 in third and way off the clock in 4th

The E15 dizzy swap is so easy even woody could do it.
If your springs are old, they will start bouncin sooner. I ran competition springs, (doubles) part noCB4A02 in my blown A14. Hit a gear too hard, and the tach used to flick around to 8K instantly.

Thrashed old A12s Ive had in the past have always been screwed out to 6K. Given enough road, they could usually do it in 4th too.
Increase to breathing, give 'em more valve spring, and some more cam. Then Bob's ya uncle!

There was some carbs on the forum for sale a few days ago.
Get a L series bosch dizzy from a bluebird & take it to a dizzy workshop & get it modified
Or you can look for a a series electronic dizzy.

what kind of electronic ign do you put on the a series?also Ive got an GX head but have no carbs to go on it do you know where i can get some??

Yeah that pretty much sounds like my old A12. 2" exhaust and electronic ignition gave me a little over 6000 rpm.