SO i found out i have the L99 intake and i dont understand why its on my car. my car is a 96 TA ws6. is it supposed to come with it or did i get messed with? i know my block says 347 on it and it has the 5.7 stamp, but i dont know why i have an L99 intake. Can i bolt up a regular lt1 intake on without a problem? the casting number i have for the intake is 12552138. I need some info please!

 

Isn't the LT1 block a 327, not 347?

 

thats not a lt1 93&(94-97) manifold by part # , post a pict of the manifold and engine , I am sure someone can help you out and tell you what you have

 

lt1 block says 327, no idea what the heck you got.

 

He has the intake manifold off the 4.3L L99 "Baby LT1" that was used in the Caprices. I'm not sure there's actually any difference between that and the 5.7L manifold.

 

I recall that I took a #630 manifold off an L99 a few years back. That number is also found on LT1 motors. I believe that the manifolds for the two engines are virtually identical.

 

aww crap, sorry guys i mean 327, it was a typo. but yea,i checked the numbers and i do have the L99 intake. And now im wondering how in hell did it get there! unless the previous owner did it. but he didnt mention anything about it. What is the main difference between these? all the info i keep finding is that the ports are slightly smaller on the L99 but will still work on all 5.7 blocks and heads. Either way i bought an actual LT1 intake. Is there anything i should know about the L99 intake that i can post up as info for when i sell it? i dont want people getting anything different than what they need.

 

here are the pics of my block and some of the heads. if you zoom in alittle you can see the numbers. This is the 5.7 Lt1. ill take pictures of the intake tomorrow and post it.

 

The 138 intake while found on L99s is not L99 specific. Matter of fact they are fairly desirable far as the Stock Eliminator guys are concerned so they can't be all bad.

I am running a 138 intake on my car with fairly light porting, if it is a handicap I wonder what this thing would do with the "right" intake.

My car came with an L99 and that is where I got this particular intake.

If it really bothers you though I can ask a couple of the Stock Eliminator guys if they are still looking for more 138 intakes and they could maybe trade you a different casting.

 

well i already bought an "actual" lt1 intake, so ill just get this one cleaned up and put it up for grabs. but i have no idea how much these L99 intakes are worth. probably not much more or less than an LT1 casting intake. what do you think?

 

Here are some pics of the LT1 (red) intake i bought and the L99 that was in my car. The lt1 is ported to fit a 58mm TB, and as you can see, the ports are alittle different. The Lt1 has regular rectangle ports and the L99 has alittle slant to it. now for my next question, what is the metal plate that bolts up on the bottom of the intake for? ( the one with 4 bolts in picture #2 on the right)Should i swap it into the LT1 or will i be fine with out it?

 

The port shapes is a YEAR thing not a LT1/L99 thing.

You are worrying about this stuff too much and if the heads are unported are probably BETTER off with the "l99" intake as it will match better.

The metal sheild is a PCV baffle, yes it is needed.

 

The shield keeps hot oil off the bottom of the manifold as well, reducing air charge pre-heat. And as Dwayne mentioned, it keeps the PCV system from entraining oil mist.

 

thanks for your replys!