If a Cleveland with a I" higher Blue Thunder intake fits, so will a Windsor.

9.5:1 is max compression for iron heads with a carb.  EFI you could go to 10:1.  Sure, you read about it sometimes, but the devil's in the details they never tell you.  Things like a cam that bleeds off cylinder pressure at low RPM, and a loose converter that doesn't load the engine until 3,500 RPM, they run Cam2 for fuel, etc. 

The compression also needs to be matched to the engine.  What's your intended powerband?  How much power are you looking to make?  You an make 1HP per cube with 9:1 compression, maybe less. 

Its like most things, you can make a lot of power on a dyno with a combination that is never going to work in an actual car.  I don't think you'll have hood clearance issues though.  I run a Performer intake with a 1" spacer and an Edelbrock 500 with a repro HiPo air cleaner on my 289.  It clears the hood by a good 1.5"  A Performer RPM is going to be taller, so you will probably have to forgo the 1" carb spacer (another thing that would likely show a decent HP bump on a dyno), but I don't think you'll need a drop base air cleaner.  I always found those kind of funny anyway.  I mean, the carb is breathing through the space between the lid and the base.  A 4" tall filter in a drop base setup where there's only 1.5" of clearance between the base and lid is the same as running a 1.5": tall filter in a regular air cleaner. 

A '69 block can be bored at least 0.040" so long as there's no abnormal core shift.  It might even be able to go 0.060".  I would bore it the least amount possible to fully clean the bore up.  That way there's meat left for a future rebuild.  I wouldn't worry about boring leading to overheating.  Every engine I've ever rebuilt was bored at least 0.030" and none of them ever had any overheating issues as a result.  So long as the components are matched so coolant flows through the engine properly (head gaskets mach heads and block, intake gaskets match intake, etc.) it won't be an issue with a properly sized radiator, fan, t-stat, and water pump.  Personally I'd avoid the 4 core radiators; I've never found them to be more effective than a 3 core.  The tubes are packed so densely that airflow through the core is restricted to the point where the additional row of tubes offers nothing in terms of actual heat removal, and in fact may make the situation worse.  If you want better cooling go aluminum, which rejects heat a lot better than copper/brass.

If you're power band is going to be done at 5,500 then there's no reason to play things dangerous with compression.  What you really want is an engine that hits hard from 1,500RPM-3,500RPM, which is where a street engine spends most of its time.  A cam that's going to make that happen is going to bolster low speed compression by having very little overlap due to its wider LSA.  I'd design it for 9:1, and take into account things like the head gasket volume, piston deck height, piston dish/valve relief volume, etc.  A lot of guys think they have 9.5:1 or more, but when you really look at it all they took into account was the chamber volume and bore.  Its nowhere near accurate, because different head gaskets can easily be used to change compression by half a point.  Personally I like to zero deck the block and set quench distance with the head gasket to 0.040".  This creates an engine that's most responsive off the line because it make flame front propagation as fast as possible without worrying about the piston smacking the head at higher RPM. 

After some checking around I found out that, 67 motor mounts (small block) are a one year only design.
Some what taller than, 68 up to (not sure what year) motor mounts, also there are 2 different lengths,
(68 up) coupes are lower,convertibles are higher. I'm hoping I got this right. THANKS FOR ALL HELP SO
FAR!   mustang stu

I'd do some reading on dynamic compression ratio.  Static ratio does not provide a useful number.  You could have an 11:1 static engine with a camshaft that gets it down to 8.2:1 dynamic and it will run fine on pump premium.  Opposite could be true, a 10:1 engine with a camshaft that puts it at 8.8:1 dynamic with iron heads will be no bueno on pump premium.

There are lots of dynamic ratio calculators out there where you just punch in your static, your cam card info and a little other info and presto… You get your dynamic ratio.

One is available free on the 71-73 mustang site.

thread-engine-and-compression-calculations