Generation IV External Engine - 408, L92 heads, what intake?

What would be a good intake for a 408. I am leaning to the GMMP carb intake so that I can spin it past 6100. I am in the process of doing reasearch on what combos are working and then buy something.

From the reading I have done it seems like the GMMP intake is my best bet, but I would always like to hear other peoples comments.

I will be putting nasty cam and hopefully hitting it with a 200-300 progressive shot.

I have a Z06 on the dyno right now that I did the motor on. It is a 402, PRC L92 heads, L76 intake, and a healthy stick. I was working on the part throttle stuff Friday and made a low timing, rich, 4500 rpm pull and it making really nice power. I'll know later in the week how far the L76 will let it go with ported heads and a large cam.

I was wondering how the L76 can actually keep up at higher RPM's, and wonder if porting it would help or if I should just look at the GMMP.

Let us know the results

I just did a quick google, and i came up with something that might help.

http://www.gmhightechperformance.com/tech/0702gm_ls2_engine_l92_heads/index.html

I am going to try the carb intake, with Nitro dave's elbow... figure its worth a shot.

I am going to use the L76 with my prc ported l92s for my 408. but as soon as the fast comes out for them I'll get that.

no ones really porting the l76s from what i was told they are port matching which has a small benefit if any to me the l76 is more visually appealing until some nubmers are confirmed on the new weiand intake or the fast intakes for the l92 heads still dont think the l76 is that baad of a choice either. thats what i have on my 414

I have talk to some people about the FAST intake for my 455 LSX I am buiding who say it will be out in a matter of months.Weather it is true or not I dont know...just thought I would throw it in there.

Id go with the Carb intake if you want to spin it over 6100. It seems the L76 falls around 6000 almost universally. Even more so on large cubes.

FWIW, I have a 375CI iron motor (.060 over 6L) w/ a comp 236/242 640/647 114cam, TSP CNC'D L92's, L76 and old grotyohahn 1-3/4" headers. I spin my car to 6800 N/A and it makes peak HP @ 6500, on the jug I spin it 7K. I dont know if I got lucky and the intake works with my setup or? but I dont die @ 6100 Im actually still climbing????
I make 440 RWHP thru a 4L80E & 9" w/ spool and 35 spline stuff. I wouldn't be afraid to use the L76 again from my experience.

right on this thread gives me hope

FWIW, I have a 375CI iron motor (.060 over 6L) w/ a comp 236/242 640/647 114cam, TSP CNC'D L92's, L76 and old grotyohahn 1-3/4" headers. I spin my car to 6800 N/A and it makes peak HP @ 6500, on the jug I spin it 7K. I dont know if I got lucky and the intake works with my setup or? but I dont die @ 6100 Im actually still climbing????
I make 440 RWHP thru a 4L80E & 9" w/ spool and 35 spline stuff. I wouldn't be afraid to use the L76 again from my experience.

My guess is that your cam and your moderate cubes is they key to the success of your combo. Combo is very very overlooked by some people. I would say you dont have much more to give on that intake. 400 cubes is pretty much the limit of the L76 at high RPM's, cam and head dependant, of course. Cam, heads, and intake are the induction system. andits all about combo, combo, combo. The right combo, the right results. You have the right combo.

KonnietheGoat,
Well It looks like I got lucky for once.

Combo is definatly the key word.

I won't be buying anything till summer as that is the down time here in south Florida, so hoefully something new comes to the market.

also, for purposes of 'do i have the right combo', its not the HP curve you look at, its the TQ curve. WHere it drops, you ran out of air. HP still climbs as TQ drops because HP is not measured, its calulated. (TQ x RPM)/5252= HP.