petrov83

I am not an engine guru so I would like your opinion if there is a better set of heads cams I could put on a stock lt4. I have full exhaust and intake already. Shorty headers unfortunately.

I don't know how to pick the best head cam package so I just went with the pre-built Advanced Induction setup. As well as TPIS MiniRam Manifold $895 and TPIS MonoBlade Throttle body $480. Any ideas on what kind of rwhp and 1/4 mile I could expect from this setup. Also let me know if I am missing any supporting mods. Any ideas on how to make it more reliable/better greatly appreciated. Also looking for an awsome tune shop in the south florida area.

Ai 212cc 21° CNC Heads & Cam Kit $3560

· Ai 212cc 21° CNC Heads - Includes New TFS Castings
· Ai Hydraulic Roller Camshaft
· ARP ProSeries Rocker Studs - 7/16"
· Comp Cams Ultra Pro-Magnum Rocker Arms - 1.6 Ratio
· GMPP 12499225 Hi-Performance LSx Hydraulic Roller Lifters
· Hardened Chrome-Moly LT1 Guideplates for 5/16" Pushrods
· Ai One Piece 4130 ChromeMoly Hardened Pushrods 5/16" & .080" Wall Thickness
· .026" Head Gaskets
· GM 10046089 LT1 Valve Cover Gasket Set
· FelPro 1284 Intake Manifold Gaskets w/RTV
· FelPro 45956 Timing Cover & Water Pump Gasket Set
· ARP 134-3601 High Performance LTx Cylinder Head Bolt Kit

mtwoolford

I can't fancy myself an LT4 guru, but I have put in an awful lot of time researching potential parts for my own LT4.

First there is the LT4 / LT1 conundrum; an LT4 head has intake runners raised higher than an LT1, and the LT4 (red) manifold has ports to match these raised runners. An LT1 (or manifold designed to be used on an LT1) will bolt up to the LT4 heads, but there will a gap at the top of the runner.....so...care must be taken that the intake manifold ports and the head ports match up.

Air Flow Reasearch (AFR) make a series of heads for almost any intended use and they have gotten a lot of good press on this forum, and they make BOTH LT1 and LT4 specific heads, all the way to full on competition, but also some pretty impressive ones that with CARB EO numbers that are smog legal. I notice you live in Florida, so this might not be an issue (lucky you).

with that said an excellent pair of AFR 195cc LT4 Eliminator Steet heads coming in at $1,800 (or a few hundred more for a wilder more competition oriented head). Add the cost of a cam, and it will be less expensive (on the order of a $1,000 or more) than your proposed $3,600 head and cam combo is . Whether or not the price increase is justified, is something I have no information on.

a stock LT4 intake manifold is a pretty impressive piece on its own. And it will bolt right up to an AFR LT4 head. Edlebrock makes an LT4 specific manifold for around $500. I have no information on how either of these stack up against your intended $900 intake, but again, one is
considerably cheaper, and the other (original) manifold eliminates this cost altogether.

One area you have not mentioned is the timing chain. You can retro fit a double roller timing chain IF you also go the electric water pump route....or.... you can fit an LT4 Extreme Duty timing chain set (which is what the factory designed for an LT4). Be prepared for some sticker shock when you price that baby.

THE 383 admiral

You did not mention your mileage. The upper end parts list you have listed. Could make short life of the bottom end. You may need to consider a ZZ4 or aftermarket steel crank, Lighter stronger rods & pistons
Or lighten up the rods & wrist pins.. give you a great response. Another intake possibility the edlebrock Pro Flow XT.. many LT owners have had great success with LE performance. Head & cam package.
Your shorties will limit your max potential. Good dual springs to control the cam selection. 21* works nice but all parts must matched increasing the speciality pats & machine work bill.

cv67

AI package sounds a little on the pricy side but their work is good

Got 392 rwhp from porting LT4 heads/intake/dougs shortie headers/tune.
It was a touch low on torque as the heads got a little on the big side of things to get there. WOT ran pretty hard though. THink playing wiht the tune and addind some fuel could have brought back some torque owner was after a hp # so....

AFR/AI would be the best choices imo

petrov83

The LT4 currently has 63,000 miles. My optispark went bye bye so I bought a new MSD opti and a tuff Waterpump. I havn't removed the harmonic balancer yet. I did buy the special tool so hopefully I won't have to remove the engine from the car. I am trying to do all I can w/o removing the engine. I will be keeping it NA.

petrov83

I need to read more I wish I had a proven parts list. I can't figure out cam size vs head volume vs velocity and so on... I would like to future proof my head for a 383 setup eventually.

THE 383 admiral

If you are considering building a 383 and changing intakes.. some of your current parts may not be fully beneficial.
You would not have a cookie cutter LT based engine.. to purchase a proven kit.
You would also need to blue print the block for the 383 setup.

96GS#007

If the plan is to go to a 383 in the future, then you need to buy components that will support your goals. In addition, you need to define what power levels you're looking for and that will define the part specs.

Here is my 383 build. There are several other posters that have built and documented their builds as well. Remember the cardinal rule...Fast, Cheap, or Reliable, pick any two.

petrov83

I would like to get over 500rwhp for a 383 build and in the 10s 1/4 mile. Reliable street car.

cv67

Youre going to have to build the stuffin out of a 383 to do it

It can be done though

You could need close to 600chp to do this and it isnt as easy as most think. 500chp or so is easy....550 youre pushing reliability, more than that youre pushing the limits of the block.

If you can afford to build more cubes you can build reliability into it, rpm makes hp but kills engines early.

Weight reduction, track time and chassis tuning can go a long way towards your goals.

THE 383 admiral

Honestly are you being serious? First you have a upper end parts list proposal.. 21 deg setup then later you want to take that all back apart to build a 383.. most of your parts will need to be tossed out
Now you want 500+ rwhp NA.. this is going to be one huge expense.. the life of that kind of build will not live to long as a street car. my setup is not extreme all out racing. But very serious. 400 RWHP before any tuning

96GS#007

If you seriously want street car reliability and power like that NA, ditch the LT4 and move to the LS family of engines. The LT4 based engine will be on the ragged edge...barely able to/shake your teeth loose idle quality, mid to upper teens for gas mileage at best, probably needs an aftermarket ECM to really be tuned properly, etc. Then again, that may be your ideal street car, different people like different things

Next, re-read the cardinal rule....Fast, cheap, reliable. Pick any two. My poor little 500+hp 383 picked fast and reliable. It cost $10k in parts but I beat on it for 3 years on road courses and could drive it on a 500 mile road trip with complete confidence while knocking down low to mid 20s for gas mileage.

cv67

^^
Least you built smart.
Went for hp doubt it will make 500 at the tire...for now
Cam still lopes at 2300+, 7-8 in vacuum, mileage with a 6 spd is probably avg single digit (fortunately I dont care) and will probably die prematurely from some type of valvetrain failure even using a lazy ramp

Fun? Hell yeah, like nobodys business!

Would I trust it on a 500 mi road trip repeatedly hell no.
It will break - thats just a built in "gotta accept" when doing a motor like this

96GS#007

Just to clarify, my 500 is at the crank, ~450 at the wheels. Idles at 800rpm all day long

petrov83

If I drop my car at a shop to change my clutch,flywheel, heads intake and put a cam how much do you think labor would be?

THE 383 admiral

With your future projection. And you need a shop to do your work. Just sell your motor.
And purchase a LSX crate motor. Your covered right out of the box. You will need one strong clutch.

96GS#007

$2k+ at a reputable shop. Labor ONLY. Add $4k for nice parts...ie AFR 195 or 210 Competition Ported cylinder heads ($2k+), custom spec cam ($300), intake porting ($400), clutch setup ($1k), plus all the misc little junk like gaskets, seals, etc that sneaks in there and people forget to include in their budget.

petrov83

I guess I'll shoot for 400rwhp and just leave it at that until i save up for an lsx motor.

petrov83

what happen to the lsx454? All I see now is the lsx440.

THE 383 admiral

Jegs 9,608

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