So I bought this motor for 250 and the guy said it was a small port head on a big port block and i have no idea if it is a 7 rib or 3 rib (I have a suspicion it is 3 rib).
So If it is a 3 rib then are there any mods that need to be done to get it into my 87 car and are there any restrictions as to the amount of power you can get out of it and whether there are any major differences.
 
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yes it is a 3 rib block. 7 rib blocks have more ribs running down around the welsh plugs, and some running across the block. They are the same in regards to fitment, they are identical, just not as rigid. If your car is n/a, you wont have any issues unless you were dreaming of 10, 000rpm+, as it will not do your crank or main bearings any favours. if it is a s/c engine, it should be fine, and high power turbo applications you would be best finding a 7 rib block, or sleeving the 3 rib and getting a main cap girdle from mrp.

Is there any modifications that need to be done to the block to get a rpm up to 9,500. I am a p plater and what to have some more power but dont want the engine to die quickly

how regularly do you want to turn the engine to 9500? if very regularly, dry sump would be required. if not very often you maybe able to get away with a wet sump using smallport oil pump.
 
there is a good thread here about getting revs/power out of a 4age. 
 
http://www.toymods.org.au/forums/tech-conversions/78846-how-high-can-16-v-engine-revved.html
 
xero is a good guide on that one, he knows his stuff and his engine is golden. but still he has spent thousands $$$$ and only really makes 119rwkw. I know the head porting and oversizing cost him a few grand.
 
this is all based on a 42mm crank though. Billzilla seems to think the 40mm crank is also quite good, will hold upto about 10,000rpm, but the oil system fails first. there is also speculation that the 40mm in the 3 rib can make the revs easier than the 42mm due to lighter components and less friction due to smaller surface area of the bearings etc. but I think that is just speculation.

for 9, 500rpm, my engine held up with 11psi for 12 months with no issue until the supercharger died. If I were doing it on the cheap, I would use blacktop pistons and rods, arp rod bolts and main studs, ladder caps from tomei or mrp, and have the rotating assembly balanced. to still be making power enough to justify revving it that high, you would be looking at bigger cams at the very least. if you were prepared to spend, I would be shopping from the toda catalogue, they make very light strong parts.