This kit GM partsdirect offers for like $2075, who here has it? What are your expirences with it? Also did you do the install yourself, and what in addition to the kit did you need or suggest getting What should the dyno see at the rear wheels with this kit and my mods?

 

It's smarter and cheaper to just port your LT1 heads and add a cam...

btw you can find MUCH more on this subject using the search function...

 

Searched a few threds and could not find any info on this. With the LT4 kit, do you have to upgrade the fuel system (pump, injectors)? Also, does the lt4 kit come with springs,retainers, etc...?

 

just get heads n cam ...you can get ported LT4 heads from GM for 900...plus a 250 dollar cam or even cheaper LT4 cam..Lt4 intake w/ is about 200 and your good to go.

 

Has anyone done this conversion kit on their 1993 or 1994 LT1? I was reading the ignition system was little diffrent in 95+ LT1's, what had to be done on a 93/94 for it to work?

 

the differnces in the optispark(ignition) are minor but they are there. if you have a 93 or 94 you have an unvented optispark. the cam from a 95-97 will work but you have to pull the dowel pin out of the 93-94 cam and put it in the cam for the 95-97. the dowel pin is shorter on the early cams. thats it. see minor but if you dont do it it wont fit right. Trey

 

I am upgrading my fuel system as well as installing the kit. I am having the 30lb. Ford injectors installed along with a 255lph Walbro pump. Also a CSI electric water pump and Impala SS head gaskets (raise compression a little). I had my LT4 heads ported by Lloyd Elliot for $400. The kit comes with the heads assembled and complete. Some guys complain that the springs are too weak and get heavier ones, but I've been assured by several knowledgeable folks that the springs will last a long long time as long as you don't put in a larger cam.

If you haven't guess yet, I am having my kit installed rather than doing the work myself. I would have liked to do it myself, but don't have a garage here to work in. Price for installation is $1500 which I would have liked to spend on something else, but now that it's almost done I'm happy that a pro is installing it. With an auto I'm hoping for 340 rwhp, maybe a bit more than that (350?) because of the ported heads etc.

 

thanks all, looks like i am gonna pull the motor. Trans and back of motor is already out, looks like its going out the top :-)

 

I am debating getting the LT4 conversion for my truck, think i may have warped a head.

I am doing the search for lt4 conversions and all I keep coming up with is stupids posts like this one I quoted. If you all don't have any good information, please don't post, you are just polluting the friggin forum with useless ****.

Has anyone installed this? Stock. Any comments, complaints? I appreciate any feedback. I would rather go w/ a LT4 conversion, that way on down the road I can get those heads ported and be even higher up the food chain than having to report the LT1s and run into a wall w/ performance.

Thanks,

 

The nice thing with the LT4 heads is that you can grow with them later, as you say.

So far I am thrilled with the conversion, it looks great, performs better, and sounds nice as well. The cam is easy to live with and I've lost nearly nothing down low. I'm also glad I did the 30 pound injectors and fuel pump upgrade so I don't have to worry about that.

Thing gets all sorts of looks from people now, fun fun fun.

 

its a good conversion. ill be doing it myself eventually. it does however cost more. some people only care about going fast now and they are right you can get more or the same power by just working with the LT1 stuff and it will cost less too. however the LT4 is better if you can afford it. it will allow you to build on it. i dont know what kind of complications if any you will run into with your truck, but you will have to have the necessary parts to compliment this conversion. bigger TB, full exhaust, bigger injectors. these things are not included in the conversion kit i believe. tuning will also be needed. i also highly recomend a small stall converter nothing big just a 2200 or something. this is for street driven car. you may want more if you plan to drag the truck.

we are in the final stages of an LT4 converted 94 vette. the car is getting exhaust put on now and then minor stuff has to be completed. ive driven the car and it is very easy to live with. its an auto and it pulls against the brakes rather hard at idle in gear. thats why i recomend a little looser of a converter.

a friend has an LT4 converted 95 z. its a six speed. he reports that gas milage is very good almost what it was stock. power all the way to red line. runs low twelves in the quarter. very good conversion. he however is running a ZZ9 cam from TPIS. i believe this cam is similar to a hot cam. all the same it is very streetable though. hope this helps and is useful. trey

 

Thanks for the info guys, that is exactly what I was wanting to hear.

My injectors are fubar from rust in the gas lines, so they were going to get replaced anyway. Have sanderson shorty headers for the conversion, (1 5/8 primaries, 3in collector necked down to 2 1/2 crossover) goes into 3in y-pipe, 3in catgo hi flow converter, 3 in flowmaster 2 chamber to dual 2 1/2 inch out. Have Lt1 edit, laptop, need to work on a CAI for the truck, stock f-body fuel pump, 3.73s, stock tranny, have trans go shift kit to install, motor has about 65k on it, was going to freshen up bottom end, but might just slap it all back together, compression and oil press reads pretty normal to what everyone else is running.

looks like the only major things I need to do are TB, injectors, and programming, besides push rods, and converting to a gen 2 opti.

Thanks again, really appreciate the replies.

 

hey all,

did the conversion and am having all kinds of fun with it, but having trouble w/ my program. have any of you all had issues w/ idling? Mine seems like it's loading up, blms are at 108, ints are getting really low, then it goes closed loop, clears up, then starts the cycle over.

I'm going to warm the motor up and try re-adjusting my rockers to see if I have them too tight.

If anyone has a tune or datalog I can look at, I'd appreciate the hell out of it.

jeff