L31 engine swap questions

[memo43]

Thanks for the corrections
I was a little groggy when I submitted my post.
its the bolt holes on the stock manifold that isn't tapped for the new engine.
it's only on the passenger side head
the stock manifold is set up for the rear most bolt hole.
the vortec motor does not have this hole tapped.
I have all the bolts installed minus the very last one.
Wishful thinking that I don't have a leak there. although I plan on getting the ram horn later this week an sending it off to have the exhaust re done.
hopefully I will be able to get some pics posted later today

[gmc684x4]

I have played with many l31 heads including new from gm
Pull the manifold off I suspect a broken bolt in the last spot or your original manifold is cuped at the back not letting bolts to line up

[memo43]

Well got the engine fired up an running, ordered a set of summit ram horn manifolds
Ended up with a 5-9psi elec fuel pump in front of the selector valve.
As well as dual windstar fans controlled by a hayden 3647 dual dual control unit.
Need to adjust when the fans come on, engine barely hits 190.
The bad I have to re do the oil pan gasket.
The fel pro 1 piece leaks right at the base of the timing chain cover an oil pan.
the timing cover is new as well as all new gaskets.
Maybe go to the thicker fel pro gasket( after measuring oil pan depth), after doing a search on here as well as Google.
Any advice for leak free gaskets

[memo43]

Here are some pictures of the flex plate, I've never seen one crack like that.
An one of my son doing his first engine removal, install not gona lie kind of brings back memories of when I was in my teens doing the same.