4age engine help

[Tunney]

hay there i have a small port 4age.

im thinking of running some cams and a portjob in the head just a coupple of questions.

1. will a bigport head fit on a smallport block ?
2. whats the main differences between small port and big port engines

cheers

[sundee]

1. yes, all 4a blocks + a series heads are interchangable.
2. its all in the name, small port has smallports and a big port has bigports
Bigports had TVIS,

some links

[DAMO46]

Over 200hp the bigport head will flow better under 200hp the smallport head will work better, from the info you have given sounds like you better just stick to smallport unless your planning to spend some big $$$.