Ive searched this but still cannot make any sense !
Here is a couple of pics of my engine.
Please, please, please can someone tell me which I have.
I need to order a balancer - thanks in advance

 

Does the big lump on the crank outside the block mean external balancer?
Its a 350 block originally - just been overbored I believe?

 

that is internal balance 1985-earlier engine;'86- later has weighted flywheel/flexplate,but the same crank damper is used on the front.

 

Internal.

 

Can't tell if it's internal or external; the part you showed looks the same for both.

What's the stroke?

 

You can't tell by the crankshaft flange other than it's a two piece rear main block.

Unless you're using a factory 400 crank to make a stroker, it will be internally balanced.

 

I've order an internal one so hopefully should be ok !
Thanks for you the help guys.
I've no idea on the stroke I'm afraid.
I bought the engine built up - supposedly from a guy called Wild Bill in california.
It was built to put in a Porsche of all things in the uk.
I got it from the guy who never finished the Porsche !
Its got a stamp under the inlet manifold on the edge of the block saying 0.40 which i was told is 40thou overbore. ?????
Its got Edelbrock alloy heads that have been worked on - the ports have been opened up and flowed.
Its got Competition Cams pushrods but and the cranks been balanced along with the pistions which have each of their weights written underneath.
Alledgedly good for 450 hp on UK fuel but who knows!
Its going in over xmas so prepare yourselves for questions as i go !