I'm getting ready for a rebuild on my LT1. I'm picking up my LT4 aluminum intake tuesday. Going 1:6 rockers(need tips on brands) What springs should i go with? probably going to supercharge later down the road. changing exhaust to Kooks true duals. headers, etc. It's an A4. need help on picking a stall. going with Yank, not sure on which though. Just a daily driver type car. will upgrade fuel system before supercharger. What else do I need? Consider? Any pointers would be great. Thamks Oh and which TB? 52 or 58?

 

The LT4 intake is NOT AN UPGRADE, depending which LT1 intake you have the LT4 ports are either the same or SMALLER.
If you modify the LT4 intake to fit LT1 heads you ruin any potential advantage it could have had in skilled hands with larger heads. In other words either do not buy it or buy it to flip it.
Next step is to forget this misguided assumption you have that the LT1 intake needs to be swapped, for what you have suggested as mods I would not even bother porting it.

Far as TB I would say consider a stocker rebored to 52-54mm they have fewer issues than all the aftermarket TBs and wont be an emissions testing hassle.

For springs the LT4 springs are a very good match to the stock cam with 1.6 rockers.

 

GM LT4 intake or Edelbrock? What heads - ported? GM LT4 intake will not bolt up to GM LT1 heads without machine work. Will compression ratio be reduced at this time to allow future S/C install? Is displacement being changed?

To select valve train components, and set stall RPM you need to provide cam specs. What rear axle ratio?

What is projected flywheel HP? That will determine if you need larger injectors.

 

It's the GM red top. 3:73 is going to be the rear end. I'm basically going to convert my LT1 to a 4. So all machining will be done to that make that conversion. i'm shooting for about 300rwhp before S/C. when i do supercharger later on will mod/tune to need. have the 24x conversion already going on with rebuild for easier tuning. what about that GM hotcam? needed?

 

There is no machining to make an LT1 into an LT4, only a pile of mediocre at best parts that offer relatively little gain for the expenditure.

If you want 300rwhp before the SC all you need is boltons.

I STRONGLY encourage you to stop trying to purchase all the wrong parts and do some research first. You are headed for an expensive, mediocre performing mistake.

 

i think that i seen Fred post a web site with LT1 v/s LT4
this is the web site ( grand sport registry ) that should tell you
everything you need to make your LT1 a LT4 if that's your goal
if your not buying the LT4 heads your better off porting the heads &intake
that you have (LT1)and paint the intake red

 

if you can't find the website maybe someone can post it for you

 

Unported LT4 heads don't come close to the flow of well-ported LT1 heads.

LT1 vs. LT4

http://www.grandsportregistry.com/lt1vslt4.htm

There is absolutely no sense in "converting" an LT1 engine to an LT4. It's a huge waste of time and money. Simply improve on the LT1 parts you have.

 

I could post it but why help the guy do things poorly?

The full LT4 HOT setup makes 425fwhp in a perfect dream world, guys have exceeded that at the wheels with ported LT1 heads and complimentary cams.

The absolute ONLY thing the LT4 package has going for it is that it is all GM stuff, but since the OP is asking for brand of rocker and talking about a blower he is not looking to go "all GM". Sounds to me like he wants a quicker car and just has some poor ideas about how to get there.

 

most of us new guys think stock LT4 heads, intake is a up grade including myself
until looking threw alot of threads. Look at post #4. I was thinking that he was looking to build
a LT4 since he was buying a LT4 intake which is pointless without the heads
that's also pointless better to port what you got are buy the good stuff

there really need to be a sticky for getting hp out of you LT1

 

that was the point of the thread actually, hence a few tips title. Found a good deal for LT4 intake(GM) and obviously from factory the LT4 had more power. So figured it would be a way to go. So you can un-light the torches guys. Hahaha. I'm totally fine building a better LT! with rebuild. Just point in the right direction please. I'll skip the intake and put money torwards what i DO need. Thanks for the help!! Saved me some $$$$
So basically I want a good fun daily with quality parts. Buying parts first before the re-build..... do i need a rebuild? 136XXX miles on a 1997 Z28. Runs good. just thought it should before adding more power to it. and advice for a stall. 3000? higher or lower for a DD. Thanks again!!

 

My car(94 T/A) made 320.4/324.4 @ the wheels with the following mods. Not saying my numbers are good, or bad. Just reporting what the dynojet dyno spit out. This was back in '98 with a Hypertech Power Programmer(never did get a real tune with that setup.) So if you're looking for 300 HP, here's how I obtained it.

Lightly ported heads, AS&M shorty headers, stock cat, cheap 3" catback, LT4 hotcam, 1.6 roller rockers, and accel 300+ ing.box. NO intake work and STOCK TB.
Also 160 degree stat.

Mike

 

The hypertech has been shown to slow down cars, really junk.
The Accel 300+ either makes no difference on my car or might actually slow it down .05 seconds.

The LT1 intake manifold has supported solidly over 400rwhp without porting.

The aftermarket sells a LOT of junk designed to con you out of money much more than it is designed to help the car make HP.

 

I compared a Hypertech tune with a stock tune once and what they did was back some fuel out of the overly rich part of the rpm-based enrichment table used during wide open throttle. Timing was kept stock if I remember correctly.

 

the stall needs to match the specs for the cam and rear end ratio
At least that's what i read on this site but alot of people recommend
3000 or more i have no experience in this so i asked someone
at the track that had a fast car and he said no more than 2800
on your daily driver hopefully he will take me for a ride in his
and then i should know what its all about