rad cams,high compresion, vibration 3500rpm help

[dannydoo]

I need some input.

xe282hr cam
dometop 11.5.1
vic efi intake
rpm 202s
long tubes
stock balancer.
billet flywheel,dual centerforce
moroso drag pan,main girdle etc etc

The engine revs smooth as silk up 3500 plenty power
exactly 3500 it starts vibrating and smooths out a little as rpm s climb,Ive taken it from 3500 to 7k and it loves the higher powerband .If someone said "its normal" I would prlly be able to live it.
The vibration is both sitting still and driving.It makes almost no difference if the clutch is in while sitting,just makes a slightly difffernet wiz in the gearbox.
But the sitting still out of gear vibration makes me think its the clutch/flywheel/balancer

I kinda got the motor on the humbug so I dunno if its supose to use race gas or not?would that make it vibrate?
is the stock balancer causing this?
Is it true the balancer must match the flywheel?
How do I know if Im suppose to use 28oz or 50oz?
I see people with vib problems talk about their shifter vibs like crazy,mirrors shake,steering wheel shakes,etc
IS THIS NORMAL sometimes with radical type motors?

I dont know where to start,IM getting depressed I did sooooo much work to this thing.
I did a complete aode conversion to tko and complete motor swap by myself and I pulled the tranny in.out 4 times exhaust off 7 times motor in/out 2 times
Its been up/down on the lift over 30 times at least.
I did a full week of tuning w/major frustration and a pih swap w/ decent sucess.
IM ready to give up
I dont trust bringing it to anyone because I see what happens to cars"especially fun cars"that get droppped off at shops.

where do I go from here?

 

[86bluecobra]

well if it is a 5.0L then you are a 50 oz wieght. it maybe a good idea to upgrade to a sfi approved balancer anyways see if that gets rid of the problem. I would say that vibration is not normal. btw do you have solid motor mounts? sometimes this causes more vibration. did you build this engine?

 

[dragnazz5.0]

with a motor like that i dont see the stock balancer doing much or lasting very long. id try a fluid damper or something of that sort

 

[Grn92LX]

What size engine is this?

What is the assembly balanced to?

 

[dannydoo]

I dont know what is was balanced to but it was correctly done/
300 stroke fms crank
grind 010 010 w/bearings
decked 007 both sides line bored etc etc
eagle sir rods
kb pistons fly cur for reliefs
fms flywheel main girdle
cloyes roller
arp oil drive

I believe its a 306

will a motor that neds race fuel do that? or will it just detonate?

the mounts are not solid theyre new stock.

 

[Grn92LX]

Does the balancer wobble at idle? Why do you have a stock balancer on a high revving engine like this? If you need a new balancer i'd go with a light weight romac.

 

[dannydoo]

I dont know man.I got the motor complete.
The reciept said high performance balancer "maybe cobra?" But Theres a chance someone swapped my balancer and put a stocker on.It dont make sense to me either.But my motor was at a "friends"house for a couple months b4 I put it in,and he wanted everything on it.
IM gonna check his car in a little while,I knw hes too cheap to buy one and he didnt have one so ....
I guess a balancer would be the smartest first move for this...