I have a serious problem!!!

lets bring this post back up again,

95vert did you figure out what it was i am having the same trouble in my 89 347 swap,,

as some of you know i built a 347 outta my stock block, killed the rings and valve guides, and now have built a new 347 outta my new Dart Iron Eagle Block,,,, well ive had some problems with it here and there, but the main problem i have now is when i went to the Dyno last thursday to get a chip burnt for it and the 60#ers we made the first pull and it ran lean up to round 3500rpm,,,

i have the CRANE HI-6 and 92 coil

after we got the chip burnt we put it to the test, started the run and it cut out at like 5300rpm,,, we were like WTF,, well tried it again and cut out round 5300rpm, so i checked all my grounds and upped my rev limiter on the box to like 8000rpm instead of 6200rpm,, it made a pull to 5600rpm and cut out,, we waited for it to cool between every pull and the next two pulls it pulled to round 6100rpm, i upped the rev limiter to 9100rpm thinking it might be the box and it cut out on the next pull at like 5500rpm,, we were like WTF,,,,,

anyway took it out last night to try my brake vacuum canister install and ran it up and it cut out at like 4000rpm in 1st, then got it on the highway and in 2nd and 3rd it cut out round 5300-5600rpm somewhere in there,,,

i didnt have this problem when i had my stock block 347 in it, and the only thing i have changed besides the placement of my ground on the ign box, is that i hooked a tach up to it and i have changed the ign module on the dizzy,,,

has anyone had this kinda problem with their boxes???? is my box shot??? tonight im going to hook up a better ground and put one directly to the battery, and run my dials around on my ign box to make sure its not sticking on the inside,, any information or experiences with this would be greatly appreciated thanks guys,