recently helping my friend gettin a fd he got back on the road
 

my buddy from work got a 93 rx7 that sat for like 11 years but have so much old school parts on it....when it was running it was featured in turbo mag....has the old shool veilside kit....racing heart c2 19in..tan interior which is flawless....some goodies under the hood too....some expensive coilovers....the last owner bought it for 20,000 like 12 years ago my buddy got it for 6000 because they grew up together and it needs a rebuild...so what would be cheaper a rebuld or just drop a JDM 13b in it...:)

Even if you buy a new block I highly suggest a rebuild. However, you can purchase j-spec 13B engines that have been compression tested, they should run fine.

Both will cost about the same, a budget rebuild will cost around $1500-2000+ reusing as much as possible but replacing all the wearable seals.

However a solid rebuild using the best quality parts could run up to $4000, the higher quality the rebuild the longer it will last and the more power it will potentially handle.

Here's what to tell us so we know what is best.
1- how much money are you working with
2- how much will the car be driven (daily/leisurely)
3- what kind of power are you wanting to make

Edit- In short, neither are really cheaper or better when doing a budget rebuild or buyimg a jdm used motor, you get what you pay for. Either could last a while or it couldn't, it all depends on the condition of the engine you're rebuilding or buying.

Www.rotaryresurrection.com has cheap rebuilds

You're in California....know that a jdm engine won't have emissions, and IIRC in some cases your car's harness won't play well with it. So if you do that jdm engine for ease and simplicity, it might not be so.

Just tell him to do a rebuild but using only solid quality parts.