Lingenfelter is good, But I would bet their numbers aren't going to match what some others are flowing that are hand porting and bench flowing. The one thing I don't like is that they don't provide flow numbers so you can't compare what their heads flow compared to others.

Couple other things:

Also note that if you want the heads finished, ie, removal of the CNC milling, that's an additional $300.

Also, those heads are set up for their cams, which are 550 lift. You're probably going with a bigger cam then that, then you need different springs, that and if they need to cut the heads for the springs, the price may go up a bit as well.

I had my heads done in 2000 by GTP, originally as stage IIs, When I decided to go faster I sent them back to have additioanl porting and larger exhaust valves. Haven't heard allot about him in recent years, not even sure his shop is still open? I did find this artical:

http://www.chevyhiperformance.com/te...ine/index.html

Honestly, I've compared on a bench my heads to a set of LEs and they are almost identical, Lyod appears to port a bit more on the roof of the track around the intake valve. Not sure how big a difference that might make in the flow numbers.

Personally I am not a fan, but a stripped Fbod with a mean 383 and AI heads is running low low 9s. Advanced Induction.

the heads from bret bauer r $3k for just the casting although they r badas$$ and id love to hav them $3k is way out of my budget lol

Got spend money if you wanna go fast. My top-end redo prob cost me around 3k. So save your moneys.

By new rear, you mean 12 bolt or 9 inch or dana, right?

yes i do a midwest fab 9" is wat i hav in mind with all strange axles and center section back braced with there torque arm and sway bar and the driveshaft upgrade they hav

what about the t56?

That's the next weak link.

At 600+ HP, you are probably going to want to at the least upgraded sliders and tail shaft. To flat shift the car you may need to also go with the non-syncro set-up?

Above that you’re looking at a full race prepped trans. There is allot of controversy concerning who makes the best parts. G Force and Liberty are what the fastest guys are running that I’m aware of. Sure there are probably a few others. They are suppose to handle 900HP, of course they still break sometimes. Big RPM launches will take their tole on whatever you use.

Then the clutch is another issue. The McLoed street twin is in my opinion the best out there. It’s not bad on the street, but not something you can use in heavy traffic.

I have a friend that turns over 7500 RPMs and the T56/street twin won't shift propperly at those RPMs, he went with a GR5 (G-force built 5 speed), this is clutchless and can be shifted about 7500 RPMs, shifted via a vertical gate. and this does have a proper SF rated bell housing too. Car has amazing shifts going down the track! I have no idea what that setup cost him. Another item on my wish list!

One thing that is really a big issue for us is that no one currently makes a blow proof housing. A group of us have been dealing with McLeod to make them, been a long process, and it might just be a one-time run of them. For now we’re using trans blankets as a safety net. Even so one guy had his clutch explode and torn him and the car up pretty bad. He was lucky to not loose his right foot or leg, pieces of the clutch and flywheel exited the car through the dash, windshield, doors and fenders! The blanket stopped allot of parts or it could have been allot worst!

Spend the dollars on a trans blanket! Best purchase I hope no one even has to use!

Sorry to run on and on, but allot of people don't realize what could happen and the saftey issues sometimes.

John

no i actually appreciate all ur input ive been lookin into blankets and sheilds and the trans will be upgraded a bit by a friend who worked in a trans shop new imput shaft and a few other things and i contacted monster clutches and there designing a clutch and billet flywheel for the lt1 so i might go with them im not sure yet our plans have changed a bit cuz after looking we feel that we could be looking at some serious #s the rear and driveshaft r pretty much desided and were lookin at 10 point cages and all the safety equipment and some lik possibly a hutchenson device might not be required in the rules but at 19 there requiered in my das rules anymore input or info you guys hav remember i will be running a 200 shot on this nitrous safety lookin at HSWs package

+1 for 4l60s, lol

John, The blow proof from McLoed is available now. They have a limited number and they are $700.00 but they have them. I was talking to Nick (NJLT1SS) at the TTP meet last Saturday and he has the 2nd one produced.

yes, and that's allot more then the target price we were originally talking about! Do you realize almost ever other BP housing out there is under $500?

The question is, how much is every other LT1 blow proof bell? They are the only game in town and they know it. Supply and demand at its finest. :nod:

Even your old smelly your feet are worth $700, no?

Hey, I'm not cheap! If I had the money right now it would have be siiting in the garage with the rest of the winter mod parts. just a bit disapointed in the pricing. We approached other vendors a few years ago and none were interested, I'm glad Mcloed stepped up. I'm running the street twin and I do know the quality of their product,

The big issue is,,, Youngest daughter just finished college, other getting married in the spring = daddy doesn't have the money right now.

Interesting article ty...

Flow numbers aren't always what you should focus on...

True, but we are talking stock ported heads, not comparing aftermarket heads. The flow numbers will give you some idea of how much work was done to the heads. If you want to compare heads on paper to make your selection, without having to bolt them all onto the same engine and run dyno results, then looking at the flow numbers is certainly the best place to start.

If you’re porting stock heads and one set flows 175 and the other 195 it is certainly going to help you decide which might be better for your application. You want them to match the rest of the engine so you maintain the proper velocity. What good is a stage III head that can flow 210+ if the rest of the internals can't? You could actually end up hurting your performance thru the RPM range.

But we're taking a 600HP Nitrous engine build here, unlike a N/A engine the exhaust side of the head work is going to be a factor, just as much as the cam selection. Looking at the exhaust side is just as important as the intake; with Nitrous you need a bit more exhaust flow that means either more flow at the ports, and a bit more duration on the exhaust lobe. If I was ordering a set of heads or talking to the person doing the porting I certainly would want to know what flow numbers he's getting.