powers84

iTrader: (4)

as the title states. you have a bunch of different casts for these engine, do all of them flow different ie: a head that came off a f-body to one that came off a corvette or buick roadmaster. i am woundering these because i just toke off my heads and the were different then the ones i bought from a guy on this tech he said they came off a f-body but i think they came of something eles. just trying to see if they flow different

BLK,97,T/A,M-6

If the heads came off a camaro, t/a, or vette, they are aluminum,otherwise they are steel.

I would recomend getting 93 to 96 f-body heads, cause acording to the folks at L.E., the 97 castings have less 'meat' on them, making porting less affective. This is the limited info i have. Hope it helps.

powers84

iTrader: (4)

thanks alot

Formula350

iTrader: (3)

Cast Iron, not steel.

dhdenney

iTrader: (53)

I have heard steel a lot. They're both ferrous so I know what they are talking about. To the OP, the cast irons flow better in stock form but I would say that all aluminum heads are pretty much equal. It's easier to port an aluminum head and they're lighter than iron so that's why they're the choice for performance.

Formula350

iTrader: (3)

Well alright, I've never heard of steel heads, but I've never not heard of them I suppose.

It's also the cooling properties that are nice with aluminum, which help us with the higher compression ratio. (other than the reverse cooling being a big factor to higher CR)

speed_demon24

iTrader: (6)

If you are going to keep the heads stock 561 heads flow the best. The 643 and 374 heads are the best for porting though.

dhdenney

iTrader: (53)

Right, although they're both reverse coolant flow, the aluminum have the better cooling properties.

96capricemgr

iTrader: (1)

I think the better cooling properties thing is over emphasized. You do understand that any heat not used to expand combustion gasses and drive the piston is waste right?

I do agree that ported 643/374 are the best choices, just think it is important to gets facts straight.

I do not know of anyone who tried pushing the compression envelope with the iron LT1 heads. I do know that a few guys who had heavy porting done later had the heads crack, they do seem to respond well to minor work thouh.

dhdenney

iTrader: (53)

Yeah but my mind feels better knowing they're cool.

Paul Bell

iTrader: (9)

From what I understand, the B body cast iron heads have some more material than the aluminum F & Y body ones. It helps a bit when doing serious porting work.