LT4 Conversion

Is the LT4 Conversion really worth the advertised 425+ hp for my stock 94Z? How much power would I actually get?

http://store.summitracing.com/default.asp?target=partdetail.asp&part=NAL-GMP3287-1

the couple people on here that i remember saying the did the LT4 conversion were over-joyed with the results. i dont know how much power you would get but everyone says its worth it...

What summit says about the product is probably true. I mean you are getting what counts -->HEADS<--, cam, and intake. WOW, but that is a lot of money. Does AFR make heads for the LT1? They might be cheaper then those GM LT4 heads and I am sure they would make better power. $2300 I would expect a 500+hp motor not a mere 425. For my engine I could purchase the Holley systemax kit for an entire grand less then that and acheive the same power rating. That kit includes heads, cam, intake, and some other misc parts.

What summit says about the product is probably true. I mean you are getting what counts -->HEADS<--, cam, and intake. WOW, but that is a lot of money. Does AFR make heads for the LT1? They might be cheaper then those GM LT4 heads and I am sure they would make better power. $2300 I would expect a 500+hp motor not a mere 425. For my engine I could purchase the Holley systemax kit for an entire grand less then that and acheive the same power rating. That kit includes heads, cam, intake, and some other misc parts.

FYI - I found that the AFR heads I found are priced at $2500, just for the heads. http://www.proficientperformance.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=PP&Category_Code=afr_heads_gm_lt-1_street_180_comp_legal

Do you know of any others sites that have the same or similar parts for less?

I'm doing the LT-4 conversion to the lt-1 I have lying around...

I'm doing the LT-4 conversion to the lt-1 I have lying around...

You're gonna have to keep in touch and tell me how it goes. Where did you get the kit from and how much did it cost you? Are you doing the install yourself? Did you get any other upgrades like a heavy duty timing chain or upgraded injectors? Sorry for all the questions, just really curious.

Wow stuff for new Chevys are insanely expensive. I dont know what to tell you man. I like LT1s and LT4 and all but man I am sure glad I have my good old fasioned Gen I SBC. I can tell you other head manufacturers but I am no LT1 expert.

You're gonna have to keep in touch and tell me how it goes. Where did you get the kit from and how much did it cost you? Are you doing the install yourself? Did you get any other upgrades like a heavy duty timing chain or upgraded injectors? Sorry for all the questions, just really curious.

I will most likely order it on monday or tuesday, I saw the conversion kit in the last Summit catalog. Yes, my dad and I will install it our selves

Are you gonna put your car on the dyno before and after you complete the install to see how much power it was actually worth?

im thinking about having it done if i get the Trans Am this spring.. i just wanna be able to hang with the big dogs.. (formula and hypsi) i'll likely get the kit from Summit as well..

I'm too lazy to do a search but I think that summit is one of only a few places that have the kit. Isn't the LT4 only offered by GM?

as far as i know.. but you can likely pick it up from someone else.. i've seen people selling the parts on ebay.. however i have never seen the full kits on ebay..

Yeah I'll try and find a place around here where they can test it at the crank because this engine isn't going into the RS I have now

i've heard that the lt4 conversion was overrated & it would be better to just supercharge your maro and you'd end up happier

i think that the conversion would be more economical than forced induction. he wont have to build up the rotating assembly with the conversion. plus, if you do the conversion and later on supercharge, then you would really see results...

An LT4 plus a supercharger...be putting out some serious ponies...

the only way to fly...

Now a circular debate LT4<------>Supercharger...hmmmmm
Maybe I'll just get a blown 427. Ha.

heres the big thing with the LT4 conversion.. the cost.. its relatively cheap compared to forced induction.. a supercharger is gonna run over 3000.. closer to 3500, where as the conversion kit is only 2300 from summit.. im pretty sure tacomaman has the LT4 conversion on his 94 Z28 i think it is.. i would send him a PM and see how he feels on the subject.

i just checked out that kit, its pretty impressive. although i already put on everything in that kit on my lt1 cept for heads and intake. i have the "hot" cam (which isn't highway legal :evillol: ) roller rockers and stuff. plus i have put on more tense valve springs and a heavy duty timing set

If I were to have the kit professionally installed and tuned, how much should that run me? Just to get some idea of how much more to add on to the actual kit.

how about doing the lt4 conversion and supercharging it..... :evillol:
but it would cost you 6k+ plus you had better build up your stock tranny,
unless your car is a t-56.

thats a good question. it will prolly cost you a load if you take it to a shop. if you have like a speed shop around you i would think that might be a little cheapier, but its hard to say. one thing to make sure is see if the shop will take the engine out or do the work with the engine installed. that will make a huge difference in labor cost...

Hey thanks, I never would of thought about someone taking the engine out or not. That would cost more. I'll make sure to bring that up when asking around for costs and stuff.

I think that @ $2,000 for 400-425 hp with parts that are guaranteed to work together is a pretty good deal, considering what you are getting. Here's a couple of other prices to compare with. I know summit offers fre shipping, but not sure about the others.

http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=pk12550630

http://www.sdpc2000.com/search.asp?searchterm=lt4+conversion+kit&doQuery=1

Hope this help some.
Kevin