Hi,

After weighing the pros and cons I went ahead and ordered the full LT4 conversion over at Gmpartsdirect. Several benefits: all the parts are GM, everything I need comes with the kit (except the timing chain and tuning, but I also ordered the former and the latter won't be a problem.) Plus the price isn't too bad, and with 104k on the ticker, a lot of the new parts in the heads as well as a new cam will be, at least in my imaginings, good for the engine.

I'm going to pocket port the heads, been doing lots of reading up on that.

I'm excited to see my nice new red intake

 

What comes with the top end kit?

 

DESCRIPTION: LT1 to LT4 Conversion Kit
A bolt on LT4 performance upgrade for your LT1. The LT4 conversion kit includes parts needed to change the top end of the LT1 to LT4 specs. Conversion kit includes: 2 Cylinder Heads P/N 12363287, 1 Intake Manifold P/N 12550630, 1 GM Performance Parts LT4 Hot Cam P/N 24502586, 1 1.6:1 Aluminum Roller Rocker Arm kit P/N 12370839, 2 Head Gaskets P/N 12551488, 2 Intake Gaskets P/N 12367777, 1 Front Timing Cover Gasket P/N 10128293, 1 Water Pump Seal P/N 10217886, 1 Front Crankshaft Seal P/N 10128316, 1 Oil Pan Gasket P/N 10108676, 2 Valve Cover Gaskets P/N 10108625, 2 Exhaust Gaskets P/N 12552470. Also includes: 1 Distributor Seal(1995-1997 cars) P/N 12552428, and 1 Distributor Seal (1992-1994 cars) P/N 10128317, but only one of these is used depending on apllication. Not included in the kit, but recommended is the "Extreme Duty LT1/LT4" timing chain kit P/N 12370835.

 

N if anyone's curious, my further rationale is this: while you may be able to port the LT1 heads to flow better than STOCK LT4 heads, the LT4 heads can in turn be ultimately ported to flow more than even ported LT1 heads. Since These will be the last heads I put on this vehicle (even for supercharging much later), I decided to go with potential. Since I'm a GM purist, that limited my choice of aftermarket heads as well.

Hotcam: seemingly great deal, will have to change Camshaft later anyway with either blower or turbos, then I can sell it.

The Red Intake: Ah, yes my love, soon we shall be together, I have your bedroom all prepared.

It comes with everything but the timing chain kit.

 

Hey just for GEE WiZ, but what did you pay for the whole kit, if you don't mind me asking.

 

I'm curious as well

 

With the timing chain kit it was about 2400 shipped. The shipping along was 90, the biggest PITA with them. W/O the timing chain it was about 200 less.

That's definitely a big "ouch", but considering that I'll basically have something that goes almost as fast as a vette and possibly faster than at least an older viper for about $30000-50000 less (got my 96 used on ebay for 9k), that works for me

 

But if you are supercharging, a much better idea would have been to go w/ a set of AFR heads w/ bigger chambers.

Taking a look at GM Parts Direct pricing on JUST the two LT4 heads (complete) + LT4 intake = $1450 + the insane $160 shipping. You could spend $150 more ($1750) and get your self a complete set of AFR 190 heads (this is AFR's price, you can get them cheaper elsewhere), and get a better performing head, better valve springs, and your choice of combustion chamber size.

IMO, if you are just gonna toss a set of unported LT4 heads on the car, you might as well just leave the stockers on there, and buy the set of heads you need when the time comes. It would save you from pulling the heads that way, just toss on new valve springs.

FYI, I have almost the same $$ into my complete (with better parts) ported LT1 heads, and they were brand new casting, not used LT1 heads, and I guarantee they perform better than a set of unported LT4 heads, and I could sell them for more in the used market too than an unported set of LT4 heads. I also didn't have to shell out the $$ for the LT4 intake either.

 

I would have to agree with Joe. BTW, it was the "LT4 kit" that got me interested in joining the forum, modding, ect. After reading threads about the LT4 conversion package I just deceided to go with the mods in my sig. I first considered stock with just a 4.5 powerdyne and shorties, LT4 Package and shorties, or N02 and shorties. After reading about others cars I went with something totally different. Spent about 3k and think it was the best hp/$/time for a car with 74k miles. I am looking at 380rwhp with a tune with my setup. Good luck with the LT4 kit. Should make good power. Maybe around 330 with shorties? It's tempting to get something that has everything you need in one package. I think it was the red intake that drew me towards the LT4 kit in the first place. I went ahead and had my intake powercoated red. It cost me $45 bucks to have it cleaned and colored. You can check it out in my sig. It looks great if you polish the throttle body and fuel rails. You need to get some headers though. I heard that the hotcam doesn't make much SOTP power without them.

Jeff D.

 

there is not a damn thing wrong with what you just spend your hard earned money on. That lt4 will scream!!!! get it all put together and you wont be disapointed!!!
This dude just spend 2,400 bucks on his ride and ya'll want to sit there and tell him what he sould have done oh yeah I forgot a Blown LT4 is slow get a grip!

 

well everyone has there own opinoin on what parts to get thats why everyones cars different. ya yuo can say well you could of spent a little more and got this well you could of also spent a little more and got something better than that. there is no limit. there will asways be something better than what you got, you have to draw the line somewhere and thats were ever your wallet screams ouch!! so there is nothing wrong with what he ordered. gm parts always fit great with no problom. got luck with your new kit

 

Thanks guys I appreciate all your comments. I know that this setup may not produce the most RWHP for the money. I'm a sucker for genuine GM stuff and OEM quality, even if it costs more and performs less, I always figure that hell, those engineers designed the rest of my car so I might as well let them design as many of its mods as possible. Seeing as my goal is mainly to have a road rocket and perhaps to eventually do some club racing, with the advertised power of this package, my supporting mods, and some suspension upgrades (and c5 corvette wheels and tires), this car will hopefully be perfect for me. Sort of like the Firehawk was first envisioned in the early 90's, fast but agile.

This LT4 package seems nice because it can grow to suit my plans for my car; I can always add better/bigger valves/lifters/porting later on when I rebuild the whole thing in preparation for supercharging.
I started off at this board being in love with the LT4, thought about mixing and matching a different cam and or heads to go for more power, then decided to go with parts that were basically designed to go together by GM. Not without precedent: I got my fingers burnt a decade ago: Back in '94 or so I royally messed up my 86 TA (Big Red Mk. I)by just slapping on a Paxton supercharger on the aging L98 or whatever without really knowing what I was doing, throwing a rod, then paying $1000's to a mechanic to fix it who also didn't know what he was doing but was willing to take me and my money for a ride. He bought and mixed parts at will, ending up with a broken car that got 5 mpg and couldn't even idle right (the dawn of computer reprogramming) and exactly $10k in inheritance down the toilet. I sold the damn thing two years ago for $2500 after it had been parked for 8 years. So the moral for me was to choose parts carefully, trust the GM engineers, and *do the work myself!*

Anyway, sorry if this sounded like a rant, I really do appreciate all you guys comments and enjoy hearing about your experiences with different combinations of power parts.