tacoma

so later down the road I'll be doing some mild mods to my 89 Cummins motor, nothing major (riiiiight), thinking airflow is a good place to start.

what is the best breathing head to get for a 12v motor??? and in the scheme of things, how important is that to diesel engines??? I'm used to gas stuff.

Begle1

First of all, the "First Gen" forum is dedicated to questions regarding 1989-1993 trucks, so any detailed questions would best be asked there. (Actually, a friendly moderator will probably move this question over there in a few minutes...)

Anyways, the best breathing head would be the late-model 24 valves. As far as I know, nobody has ever put a 24 valve head on a 12 valve block. If they have, it's been pretty rare. I think that with the money spent on the swap it'd be cheaper to just get the stock head ported.

In theory, the second gen heads (94-98.5) are also better heads, but I've never heard of people even doing that swap. Come to think of it, I think that the intercooled first gen heads (91.5-93) are even supposed to be better, but I'm not sure about that...

For you're truck, depending on your power goals, you can get around 300 horsepower by putting under $500 into the turbo and tweaking the pump. If you want more power than that, you might want to start looking at getting the head ported (and O-ringed to hold more boost) for also around $500 dollars, but after 300 HP the mod money required ramps up fast.

But in general, other than porting and O-ringing, not many people play around with heads. Camshafts are in the same boat, but first gens are supposed to have the best camshafts available stock (in theory).

Forrest Nearing

none of the heads flow very well... at some point, plan on replacing your '89 head with a later style head w/ the smaller injector holes because as you start making more power, yours will crack (sooner than a later style head anyways)

you'll be much better off spending your money on a turbo, a pair of turbos, and or a good intercooler than you will on head porting (this from a guy who's got over $2k in my cylinder head)

cylinder head flow always helps, but with these engines, there are much better places to spend money...