So, I have my LT1 out of my car and torn apart. The car ran fairly well last year. First, I'll give you some background on the car.

Combo was:
Stock LT1 heads with stock valves and light porting.
CC306 cam, beehives and stamped 1.6 roller tip rockers
Pacesetter longtubes to 3 inch exhaust, no cats
52mm TB, 36# injectors, Walbro 255, 373's, 3200 stall. etc etc etc

The car put down about 350rwhp revving to 6500 (power was not yet falling off when we shut it down, but I didn't want to pop the stock bottom end) through a performabuilt auto and a 10 bolt.
Ran a best of 12.4 and a best mph of 110 in around 3000 DA

This takes us to the question portion.
The shop that put this engine together a couple of years ago for me did a pretty ****ty job. The car ran strong, but upon taking it apart, they half-arsed everything.

The header bolts weren't all in completely, and you could tell that the headers were leaking, some ports more than others.
The gaskets used between the intake manifold and the heads actually had slightly smaller ports than the heads did. Yes, smaller, lol.

SO given these two variables, combined with the fact that I will be giving myself a fresh shortblock boring the block .030 over and adding forged internals, an LTCC ignition, and revving at least another few hunder rpms or so, should I see a decent increase in power? How much were these screwups holding me back? I was amazed that my car hadn't fallen apart. These were not the only shortcuts found on the car, but I won't even get into the rest.

 

As long as you understand making something better, does not always mean better track times. Making something stronger so it can handle the power, doesn't always relate to hp gains. The right setup combo is really the best way to get the most out of your car.

 

People can only guess at HP ratings. People usually tend to believe the higher ones.

 

The gains I'm looking for will hopefully be obtained through the use of:

1)correct, matching gaskets that don't block my intake runners
2)better compression than my 113,000 shortblock provided (even though it appeared to be in pretty good shape)
3)the extra rpms the new combo can turn that will take advantage of my CC306 cam (because power never dropped off even at 6500rpm) thus improving my powerband at least several hundred rpm.
4)the ability to be able to handle the 150 shot I'll be throwing at it
5)As small as this may seem, the extra 5 cubic inches is always welcome

 

If the intake gasket was smaller than the ports they hogged out the ports, probably junk if you ever decide to make real power. Was the manifold ported too? If not then the gasket being smaller than the head port probably didn't hurt anything.

Unless they found some wacky gasket that had unusually small openings, did the gasket have gen 1 water ports or anything, was it a proper LT1 piece? Gasket matching LT1 heads/intake is considered bad without full proper port work the full length.

Header bolts being loose is because most gaskets compress and the bolts need to be re-tightened after some use, THAT IS YOUR FAULT.

Stamped roller tip rockers is a joke, if a rocker needs rollers anywhere it is at the fulcrum like was introduced after the LT1.

 

The gasket was not extremely smaller than the port, but I highly doubt the heads are junk considering they made 350rwhp through a stalled auto with just a CC306 cam through the muffler WITHOUT all the bolt ons with 113,000 miles on the shortblock and the HP curve never dropping off even at 6500.

Let's be honest here, the biggest gain from swapping the stock rockers is moving from the 1.5 ratio to the 1.6 ratio. If I were to spend the hundreds of dollars to swap from 1.6 rockers to 1.6 roller rockers, how much would I really gain? 5rwhp?

EDIT: How do I know the job was botched? The balancer center bolt was snapped off in the block. The K-frame only had 5 of the 6 bolts replaced after install. The transmission only had half the bell housing bolts in place. Just to name a few things.

Also, how is it my fault about the bolts? This was done when I had much less knowledge or experience with any of this. When you take something to an "expert" wouldn't you think they would tell you about something like that?

If a doctor prescribes a medication and doesn't tell the patient that it can't be taken with this or that, or that alcohol cannot be consumed with that particular medication, who's fault would that be when the patient became increasinly ill? If I had been a mechanic at the time I would not have had to take it somewhere, I would have done it myself.

 

all he is saying is when you have headers you have to check the bolts often, they loosen

 

Here is a tip for header bolts, wrap the threads in thread tape. I haven't lost any header bolts since I started doing this years ago. They stay tight, I usually check them a week after I finish any motor swap I've done or had the headers out for whatever reason, none of them ever even need to be retightened.

 

The bolts don't magically loosen, the get loose because the gasket compresses with time and heat cycles, then once loose they can vibrate and back out.

Seems reasonable that thread tape would stop the vibrating out but does not address the need to retighten as the gasket compresses.

 

I think I used Percy's gaskets on my headers....can't remember the official name for them, but they crush...I think they are some type of soft aluminum. I also used ARP's 1" stainless steel header bolts. I've had no issues with them ever coming loose. However the ARP's allowed me to use a rather long 5/16" boxed end wrench to tighten them.

Another issue that can be of concern is the order in which to tighten the header flange bolts. It is essential that you tighten them from the center out. If you tighten the ends before the center, a slightly warped flange will not be pulled to the heads properly(depending on which way it's warped). This can result in leaks and, maybe, more movement of the flange as it heats and cools....thus causing the bolts to back out.

 

Yes ratio is nice BUT modern performance cams/springs can put a lot of stress on the ball fulcrum.

True rollers would be money better spent than the LTCC. Since you decided to use the money argument. You could also use a less expensive brand than Comp and barely spend any more money.

 

I assume you are referring to the rockers in the LS1, LS7, etc. So GM does agree with you. It's interesting that they didn't go with a roller tip, but I guess that was a reliability concern.

 

Before they folded Crane actually had some info released about a new rocker design that was a radiused pad at the tip rather than a roller and it was going to be a very highend rocker not a budget one. Argument was made that at rpm the roller just skids around anyway it is not changing direction that fast.
Did a little googling and it was Radi-Arc. It had other features like a variable ratio through it's travel as well. Don't think it was ever sold though and no idea what happened to it once Crane was bought and reopened.

I believe they were also looking at going to a polymer sleeve at the fulcrum because again the needles don't actually change direction all that well.