A few years ago the muscle cars and the imports were two different worlds. Switching parts would have been complete and utter blasphemy. However, the last few years we have seen two developments; V8 engines in Japanese cars and Japanese engines in Muscle cars. Today we will discuss the V8 engines in the Japanese cars.
Swapping in a V8 in a Japanese car has several advantages. The biggest advantage is the torque. The americans dont say "there is no replacement for displacement." for nothing. With a V8 swap you will always have enough torque for acceleration under normal use. This is the reason why this cae is usually used for drifts nowadays as it is a pretty cheap swap and you can easily spin the tyres.
If you swap in the engine for a relatively old V8 you will have another advantage; the reliability. The Japanese engines are known to be reliable, but they will not beat the reliability of a 50 year old V8. The reason for this is simple. As these blocks hardly have any extra's there is not much that can break. In addition, these blocks are made out of cast iron, which is very strong.
Another advantage for the V8 is the aftermarket. There might be a lot of parts available for the RB25 of the 2JZ, but there are always more parts available for the V8's. This is mainly because the V8 has had several decades of R&D before the popular jap engines were even invented. Another advantage because of this is that the aftermarket parts are cheaper thaan the Japanese ones.
Dont expect the swap to come with disadvantages though. Although not every V8 is cast iron they all have one similar feature. They are heavier than the average japanese engine. As you will expect with the MX5 above the center of gravity will be placed a lot more to the front. In case you are planning a grip build, then this is not optimal. For dragracing however it is a completely different story.
Another disadvantage is that you can not swap the engine as easily as for example a B16 swap in a Civic or an RB20 swap in an S13. However, for some people that might be more to do a V8 swap.
The final disadvantage of the V8 is that they are not as fuel efficient as the Japanese engines. This might not be a problem for an all out racing engine, but if you are planning to use it as a daily it might be something to keep in mind.