Are there any aftermarket intake manifolds available for the LT1 other than the GMPP carb intake?

 

For carb yea unless you get one and drill them out yourself.

 

what do you mean by drill them out?

 

You can get a older intake and drill it out to fit the heads.One with GMPP and other with another type intake.

 

I was really looking for another fuel injection manifold, are there any other options, or is the stock piece pretty well refined?

 

The LT4 intake was considered a fair upgrade at the time, not sure on the specs but it's worth researching to see if it fits your needs.

 

Ok I thought you where wanted a carb intake. The stock or stock ported is a fair pice. There is a eldebrock but the gains if any are not worth it.

 

how much do you think someone should charge to port my intake? I plan to put a cam in the motor, more specifially the comp 07-306-8 cam (230/244 duration, 510/540 lift)would that cam be good in the otherwise stock motor, it would be backed with a T-56. I am putting a full exhaust on, and of coarse I'll have it tuned.

Thanks for all of the help and input!

-Eric J.

 

306 in a stock motor would not be good. It moves the torque range way up and likes to be spun high....I mean like 7k rpms high. With the stock heads, valve springs and intake it would be a waste of a cam. I was looking at it until I saw the XFI series cams that Comp has made and still looking at one of them to put in the car, they keep the RPM range down close to stock range.

 

Yea I dont think I would use the 306 on a stock headed motor. Although it has been done some liked other said it was a waste.
Intake porting:http://www.elliottsportworks.com/lt1.html

 

It likes to be revved but it will work just fine on a stock headed motor. You just need to run the appropriate valve train components.

The lt4 intake is actually the exact same as the LT1 intake, it just has different ports to fit the LT4 heads.

A ported intake will do just fine for anything you will need it to do. However, don't go through Lloyd. I could never get him to give me enough information to want to do business with him. Go with Advanced Induction instead.

Lastly there was a company that was modifying the Holley Stealth ram to work on lt1 engines. Do a search of the lt1 section on ls1tech.com to find them.

 

So does this mean any SBC intake can be made to fit an LT1?

 

Lloyd is probably the best out there for porting LT1 castings, his packages with head/cam combos are considered to be some of the best out there also. Someone local sent a set of Trick Flow heads to him to be ported, he got them back in two weeks and they looked awesome those with one of his cams put an ImpalaSS down the track in the low 8's in the 1/8th which that car has no lightening done to it, he does extremely good work.

As far as the 306 on a stock headed motor, I never said it wouldn't work.....I said it would be a waste since you can't get the full potential out of it on a stock headed motor, and that the XFI series cams would be a better choice, but with any cam that is put in the car, you would need to upgrade the valve springs at the least for any of them.

 

MHO I really dont know but I would say you could use most. I have seen some on other boards done with older intakes.

 

The bolt pattern must be redrilled on either the intake or the cyl heads, and the dist hole plugged. Then any SBC intake can be used on a LTx motor

Option B is to mount a vortec style dist in the dist hole and reroute the wiring up to it to delete the opti

 

Is there any computer mods nessacary when you use the vortec distributor? I understand the opti is the source of much headache in the Lt1 crowd. I understand that the '95 and up opti is vented and less failure prone, is this true? if not are there any other options out there other than the vortec?

 

If you're going to ditch the intake, opti and PCM, might as well just build up a regular SBC. The opti is only prone to failure if it gets moisture inside it, I have one on my car now with over 140k on it with no problems at all, and I have a spare that came off a car with 100k on it.

If you put a carb and HEI dist on the car, you ditch the PCM completely.

 

Most people want a distributor back there because they do not know the benefits of the opti or that water really does kill them just just dist modules

The vortec dist is essentially a cam sensor under the rotor. Its pretty much an unsealed, standard location opti

 

I'm not wanting to go carb, I'm just weighing my options, I was just wondering about the vortecs compatability with the stock PCM, I wasn't saying that I wanted to get rid of it.

Pocket,
you mention there are benifits to the opti, what benifits does it have over the vortec or an HEI?

Thanks for all of the help.

-Eric

 

The opti bolts on, no adjustment to it...the PCM does all the adjustment of the timing, advance etc etc, you want to change the timing on the car, you do it in the PCM. With the '95+ opti's you don't have to worry about getting them in wrong because they'll only go on one way. As long as you keep the vacuum lines hooked up that keep the moisture out of the optical sensor, then it will last for quite some time.

 

They're also more accurate and like the upper RPMs better than other GM distributors

 

cranks interchange between LT1's and Gen 1 motors right?

 

No...well sort of.....they say when rebuilding an LT1 to do not get the crank mixed up due to it being balanced for the light pistons in the LT1.

 

I was also wondering. with the reverse flow cooling and the aluminum heads, how high can I go with the compression ratio with an LT1 before running into problems with detonation?

Thanks for the help-

Eric

 

Some people on cz28 are running 13.1/14.1 on 93, but safely I would not go past 12.1 but
you need to calculate the dynamic CR, to determine the octane requirement.