My crate 350 came with "stock TBI/TPI" heads. What the heck does that tell me??? Does anyone know the stock stats? The cam that came in it has *203/*210 dur. @.050 and .476/.480 lift.

They are definately not vortec heads. "My stock intake fits". From what I understand vortec heads can only accomodate up to about .450 lift or so. Is that true. I got that info from ScogginDickey Chevrolet. So how can these heads accomodate more lift than the "new" vortec heads???

 

probably the cast-iron l98 heads. You tell tell for sure by getting the casting numbers.

 

didn't think about that.

 

TBI and TPI heads are completely different. There is no such thing as what you described. So, we know right from the get-go, you could have almost anything. There's no way to do anything more than just guess without a casting number. Get that, visit www.mortec.com or post it, lots of people here will recognize what kind they are and what to do.

Your cam looks alot like the stock L98 cam. Not much of a cam really, but not near as bad as some.

Vortec heads have particularly tall valve guides. It's not like they've been figuring out how to make things easier or harder on hot-rodders; just always remember, they are truck heads, pure and simple. They are meant for trucks, set up for trucks, have parts on them appropriate to trucks, and that's as far as the factory has ever carried them. They do not come set up as a performance head, for things like high-pressure springs, or high-lift cams, or any of that; they're truck heads. Lots of older heads will accomodate more lift than those truck heads.

 

That is way too much lift for an L98 cam.

 

The cam is a LT4 cam and here is the engine spec sheet. Check out the head information. See there is such a thing.
Price: $2,495.00
Part # SD300TBI


Horsepower: N/A
Torque: N/A
Compression Ratio: 9.6:1
Duration @ .050" I/E: 203°/210°
Lift I/E: .476"/.480"
Block: 2 Bolt Main Goodwrench - 1 Piece Rear Seal
Crank: LT4 Nodular
Heads cc: Stock TBI/TPI
Intake: N/A

The original spec sheet claimed 300HP for this motor.

 

No, there is not a such thing. For one thing it says head cc. That is a measurment. That could mean that they have the same size combustion chambers or same size intake runners or something of the sort, but it does not say that it is the same casting number as the tpi/tbi heads because they didnt have the same heads.

Ben

 

I know I know. I am just saying what are the specs ya know why do they give me a spec sheet with that on it? I am going to have to get the numbers off the heads.

Ok I just went out to get the numbers. Aren't they suppose to be on the back of the casting? Can't find them.

 

Head casting #s are under the valve cover, between rockers. The block casting # will be on the top of the bell housing flange behind the driver's side head.

 

I think it means that they could be TBI or TPI heads, it's just whatever crap they had, they throw on. Get some #'s then you will know!

 

Well, I guess I won't be getting those head numbers tonight then . I was thinking about the block numbers. Thanks.