Cant get full revs out of a 3.2. HELP

[ALXinNZ]

Hi Team

I have a 3.2 in the back of my 74 and since install it has been cutting out at 5800rpm. Its like a lack of spark....

I have checked fuel press and it seems fine.
I have changed coils and it is better mid range but still has the cut at 5800.
I had a Steve Wong chip installled so changed it back to standard and still no difference.
I did have an issue with the alternator when I first got it going but it is charging fine now ( high rev making it fail??)

What I have left to go on!
I had a friend follow me last night and he said the tail light on the right hand side of the car starts to flicker at high rpm just before engine starts cutting out.

I haven't changed plugs

PLEASE HELP I need a new perspective

Regards

[john walker's workshop]

if the gap is too wide between the flywheel and the sensors, they do that.

[techman1]

Do you get the same result when car is cold, versus warmed up?

Have you checked the grounds in that area?
For those familiar with the the engine compartment grounds, do the rear lights and engine compartment electrical (coil, alternator etc.) share a ground location?

Techman1

[der Mond]

I had a similar problem and what cured it was getting out the Bentley Manual and finding all the ground points I could reach on the car (there was a nice map of them) and unscrewing them, cleaning and re-tightening. In my case, I believe the culprit was after I replaced the intake manifold gaskets, I did not have the ground screw tight enough on the intake manifold riser on the left side. That messes with the DME and caused my rev problem. As soon as all the connections were clean and tight, she ran like a dream. Also, have you had CO adjusted properly? That can make a BIG difference.

[ALXinNZ]

I will do all the above and check it again.
I dont rev it out when its cold so i don't know.
The earths might be a good place to start, then the sensors. ( Great idea ) I have had all that off for the build. More than likely the issue now i think about it

Ill let you know how i get on.

Thanks alot