Gojira94

iTrader: (4)

My bad on the cc306 vs cc503 specs. My 503 is the slightly smaller of the two... also, about 74-75 degrees of overlap on that cam vs 54-55 degrees on the 503.

OddballLt1

iTrader: (1)

It probably max's at 6600 on stock heads, but with ported one's it makes power to 7K.

fireman

my CC306 with stock unported heads peaks at 6250.

jimwantsLs1

iTrader: (5)

then with the trickflow heads i can reach a pretty high rpm, which i wont want to do with the stock bottom end lol a couple times wont hurt haha

96capricemgr

iTrader: (1)

Look the majority of the input in this thread is bad.

The 21degree Trickflow is UNTESTED so right there the HP guesses are baseless. That said IMO it will be under 400rwhp some heads/cam LT1s make 400+rwhp and the masses start thinking every heads/cam LT1 makes that, it is NOT the case though.

I am certain that ported and with the right cam those heads could go over 400rwhp BUT in as cast form with a too big dinosaur cam I don't see it happening.

The guys bashing ported stock casting just used the wrong shop, they can't seperate a bad decision from bad parts, can't admit their mistake was choosing the wrong shop instead of the wrong casting. Easier to blame the casting because the old one "did not work" so now they can claim when they buy aftermarket they are "fixxing" the problem.

There are enough of us going fast on stock castings to prove that in the right hands they are great.

quik95lt1

iTrader: (7)

I had something close to this set up last year.....i was a 355 with 11.2:1 CR, TFS 195 23* heads, stock ported intake and an AI cam that is similar in size 234/242 .600/.600 but my LSA was down at a 108+4. Any way, that setup ran absolutly awesome for a 355 I turned 11.40 @121 in a 3450lb street car every weekend!!! It should go pretty good, and I also am curious at what those 21* heads will do out of the box.

Gojira94

iTrader: (4)

I thought I had one of the "non-preferred" castings. I looked back through my pictures from the build when I wanted to capture foundry marks, etc. and dsicovered I have the 10128374 casting, one of two that do especially well when ported. Like 96CapriceMgr says, even these make good power in the right hands. I had been thinking I'd taken a non-preferred set of heads to Steve when I found the casting defect in my left head (Steve fixed that, too). You can't argue with results... $1800.00 do all the headwork + assembly + intake porting, matching to the heads vs. definitely a lot more to buy aftermarket heads, work them, build them with the valvetrain hardware I wanted.

Gojira94

iTrader: (4)

A little more information for numbers on the OEM castings...

10128374 Starting in 92 is one of the 2 "sweet" castings for porting.
10207643 found from 94-96 is the other "sweet" casting.

10205245 from 1993, and 12551561 from 1996 are not especially desirable, but can still be worked to some degree if you want to have them done.

96capricemgr

iTrader: (1)

I would say edit your first post.

lsformula

There is a guy on mifbody.com named Ryan Warby (ryanwarby01) with an LT1 with TFS 21 degree heads and a LLyod Elliott cam similar to a cc306. He makes 400rwhp with full bolt ons so the heads have been shown to work. It is only 1 car but I think these heads will show that they are a very viable option to porting stock heads.