6.0 in a 91 chevy truck

[badseed91]

I have a 91 chevy single cab stepside with the original tbi350 and 5 speed. I was wanting to convert to either the 6.0 or the 5.7 ls1. What would be best? Would the extra cubes be worth it? When i say 6.0 i am talking about the 345hp version. Does anyone know the difference in the 345 hp and the 300 hp version? Also i have the 5 speed getrag tranny i dont think it will hold up. however it has held up to my shifting for 258,982 miles and it still shifts great. I want a t-56.I am looking for the best of the two engines right now. The bolt on's can come later. I just want a the best base to start with. I would like to stay away from an automatic simply because i like standards (what can i say i live in the country). If anyone could tell me what they would do i would appreciate it. I have about 6000 to spend as of right now. How would you spend it on the conversion? What engine? Wiring harness? Motor mounts? Fan? PCM tuning? etc. I just found this site and i havent been able to suck all the information in yet so i am not sure what is best by what others have said. Also does anyone know of a gauge cluster that goes past 85mph for my truck? the needle stops about where 90 or so would be and then i am guessing from there. I see all the f body guys can get a 200mph speedo conversion so why cant the truck guys get one that goes to 150 or so? How dependable are everybodys conversions? What kind of gas mileage can i expect? Where is the best place to get the engine and tranny? I know i custom driveshaft is in order most likely along with new tires because after i get this done i am going to roast the one tire that spins off the rim and then switch sides and roast the other tire. If anyone can help it would be greatly appreciated. I need to spend this money before my fiance spends it on soft flowery pink stuff.

[GMCwantsLS1]

It is kind of a personal preference as to 5.7 or 6.0L. I like the 5.7. It is quite a bit lighter than the 6.0 and in stock form makes the same horsepower. I've read that your 5 speed will work fine behind either or you could swap for a 6 speed. The 5 speed getrag tranny is suposed getrag to be very durable. The difference in the two 6.0L engines is the higher HP one has flat top pistons that raise the compression ratio.
What engine?I would look for a Camaro complete LS1/T56 pull out with harness and electric fans.
Motor mounts?I have a template to convert your V8 mounts to LS1 block.
PCM tuning?Nelsons!
Drive Shaft? A racing one would be good for the standard tranny!
Instrument cluster? You could build a custom one out of Autometer or something.
Gas Mileage? You could get in the 20s but you probally will drive the tires off! The lowest I've gotten is 17.3MPG and that was WOT dyno runs with highway driving.
$6000 should get you driving again if you get the right deals. I got mine from http://www.hpsalvage.com/.

[badseed91]

Thanks for the info. I think i will go with the 6 liter simply because it has the iron block. your 17 mpg is still better than my 15mpg on any day. Plus you have way more power. I hope to get this project rolling soon preferably before summer starts. I can get the driveshaft from a local guy in Beaumont. He builds the driveshafts for Grave Digger sometimes so he must be diecent. The motor mounts are my concern. Where can i get them? or do i have to make them myself? I hear that farmtruk (allen im guessing is his name) can get the a/c bracket made for the truck accessories so i dont have to cut my frame. I would like to stay away from that at all costs simply because i just dont like the idea and i dont feel like messing with cutting and welding on my frame. The gauges are one of my biggest concerns though. my 85mph speedo and 4000 rpm redline need to go. I want to keep a stock looking gauge cluster though. Does anyone know how to calibrate GM speedometers from 85 to something higher? I can get a custom gauge face made for any mph or rpm i want but i cant find someone to calibrate my gauges to show more mph. What about a cam? Should i go with an LS6 valvetrain setup? What about porting the heads? I know they flow great already, would porting the 6.0 heads be worth it? I have a buddy that works at a machine shop that has access to a flowbench so the cost of getting them ported isnt that much of a concern. So let me see if i got this right.
I need the 6.0 engine wiring harness and pcm
I need the t 56 tranny. Will it work with the 6.0 pcm?
I need a fuel pump. What kind?
I need motor mounts. Do i have to make them or do i have to buy them?
I want an a/c relocation bracket. Farmtruk?
I will mostlikely need a tranny crossmember i think or will mine work? It doesnt matter because im going to build myself one out of tubular steel. A buddy of mine decided that it would be funny to high center my truck on a culvert and now its bent up a little bit.
Can anyone think of anything else. Im making a list of parts so i can get this project rolling. I got my fiance to understand that i need to do this conversion because it will save tons of money in gas which it will, but it will give me more power than her lt1 z-28 and that will eat her up. She hates my other truck because its faster than her car. HAHA This is a great site i looked through every post last night and read them all. My brain is still fried from reading so much. I hope to find more info on here today.

[RedHeartbeat]

You must use a LS1 transmission with a LS1 type engine(unless you pay someone to modify your bell housing to mount to the unique LS1 bolt pattern). The 4L65E Automatic would be the best way to go in my opinion. The shifter location should be checked if you are looking to put the 6 speed in your truck. That or you could use the LT1 instead if you want to do a really simple conversion. The Corvette accessories are the best setup for a truck. I have one for sale in the for sale section here. Going with the LS1 will require a lot of incidental expenses to install including custom mounts, possible cutting of the frame to use the stock a/c location, high pressure fuel pump, custom wiring harness, exhaust, electric fans....the list goes on and on. My suggestion if you aren't married to the idea of converting your older truck would be to sell it and use the money to buy a truck with the 5.3L. It would be cheaper and easier in the long run plus you would get a modern truck with all the newer engineering improvements.

[badseed91]

I thought about an lt1 conversion but i hate opti spark. The only way to get rid of that would be to run a differant type of crank trigger. I fiances z-28 has opti spark and it works good till the water pump starts to leak through the weep hole in the bottom of the pump and eats away the seal on the opti spark distributor after the water gets in there it will short out either the high frequency pick up or the low frequency pick up and cause the car to run like shit. If it shorts out the high frequency side the car wont run at all. I have had to replace the whole opti spark set up and pump twice. Each time they lasted about a month longer than the warranty did and not only is the distibutor hard to find where i live but it costs an ass load of money. LS1 parts are all over the place and a bit cheaper as well. I thought about an lt conversion but i put that out the window when i replaced the opti spark the second time. The water pump wouldnt leak if the damn water pump drive bearings wouldnt wear out so quick. I thought about going to an automatic such as the 4l65e but i love the standard to much. it is way more fun to drive. I found an ls1 t56 combo around here for about 3500 with 30k on it but i have my heart set on the 6.0 with a t 56. Thanks for the info and advice. It is appreciated and i have thought long and hard about the dissadvantages and advantages of both and being that the ls1 motors are becoming more and more popular and parts are getting easier to find at a good price. Not to mention that it is the most badass series of engines ever made by gm i decided to stick with the ls1 series of engines.

[Sleeper]

all upsides and downsides of LS1 vs. LT1 are basically the same minus the motor mounts, and fuel pump(but if your putting a high hp motor in your truck why wouldnt you upgrade?)...both require a/c relocation, both require custom wiring, both require electric fans, and both require a new exhaust, and all are solved the same way(vette acc on an lt1 to relocate.....vette acc on ls1 to relocate, etc). LS1 can be put in anything for a lot cheaper and easier than buyin a whole new vehicle, going through salesmen, signing bank loans, and dealership papers, financing papers, etc., blah blah blah.

[RedHeartbeat]

The reason I suggest the LT1 is I have gone both ways and the LT1 was the easiest and cheapest to do. Not to mention not having to cut anything excepts wires and exhaust to make it work. Plus the stock factory guages will still work and you can put most any transmission you want made by GM in it including the stronger than an ox TH400 built to pull a locomotive. The LS1 block cannot be bored out more than .010 by factory specs and the price of stroker cranks are through the ceiling for LS1 engines. The LT1 can be bored .060 oversize and SCAT cranks and rotating assemblies are inexpensive for the LT1. Honestly, I went down the road of the optispark problems but only had to replace it once and never had a problem with it after replacing the optispark only.

Which ever way you go, you are going to have a stout setup. You might even start thinking of looking at the LS2 engine GM has available now.

[97 SS 383]

This is twice that I have read a post where someone says you can put Vette Accessories on an LS1 and that takes care of the A/C being in the way... I don't think that's correct. All of the LS1 derived engines have the A/C mounted on the lower passenger side of the motor don't they?

[badseed91]

I think he was talking about the vette lt1 and vette ls1 None of the accesory brackets are cmpatable from either engine design. I know for a fact that you can put a 400 behind an ls1 with no problems. There is one that was at the track in a z 28 last time was there. I think someone did the LS1 swap and got their gauges to work with it. I think allen has a 94 that has working gauges with an ls1. As far as overbores are concerned what can a 6.0 be bored to? There are also 6.0 blocks on ebay for about 500. That beats most machine shops or at least the one i worked at. Has anyone heard of procell? I have heard good and bad about them. I was never done wrong by them and my motor held together. There is no way i would sell my truck now. I just got it painted. With over 250,000 miles on my truck a dealer would only offer me pennys for it. Sorry bastards. If i did sell my truck and got a loan then i would have payments and full coverage insurance for a 21 year old male I dont even make enough money to pay the insurance I only work part time because of my school. I think the new trucks are a little to plastic for me. Plus i want to have the satisfaction of updating my truck. What is the ls2? I know its probably a dumb question for yall. the only dumb question is the one not asked. Also im not exactly made out of money either if i didn have that much money i would probably pay someone to do the conversion for me and not worry about the satisfaction of doing it myself. However i do appreciate the ideas and suggestions. I learn more in one hour of reading on this site than i do in three hours of history class

[RedHeartbeat]

Personally, I removed the a/c unit from my LS1 to rid myself of the headache associated with getting the unit mounted in the stock location. I cannot afford to weaken the frame of my truck by cutting on it. My truck does a little pre-running and the last thing I need is the frame breaking while I am out in the middle of nowhere.

The LS1 a/c will not work on the earlier truck unless you cut a large chunk of frame away for clearance. You will find lots of people who have done exactly that and they all claim it does not affect the strength of their frames. Street and Performance in Mena, Arkansas has an entire pulley assembly you can use with all new mounting brackets, bolts, belts, p/s pump, sanden a/c compressor and all to put a ls1 into a 88-98 truck for about $1500. That way you won't be cutting into the frame or have to find someone to cut out the chunk of frame and then fabricate the required filler panel to strengthen the frame back up. You might have a problem finding someone to assume the liability involved with doing something that may severely affect the structural integrity of something as important as the frame. I hear of all kinds of people doing it themselves but I have yet to see reputable companies like Street and Performance chopping up a frame just to clear the a/c compressor. As for fitting other transmissions, most GM transmissions will fit the LS1 but flywheel spacers have to be used and the bell housing on the transmission will need modified (2 additional/relocated bolt hole locations) to use older trannies or many of the later truck trannies onto an LS1. I bought a 2002 model truck 4l60e unit with only 6000 miles on it and had to buy an LS1 bellhousing, LS1 converter, LS1 front input housing and LS1 pump stator unit just to use it on my LS1. The LS1 and Vortech V8 engines use the same transmissions. All other V8 engines have the old bolt pattern.

The Corvette LT1 complete accessory setup works in a 92 chevy c1500 without any butchery other than having new a/c hoses built. I should have taken pics of my engine compartment when it was all together, it was sweet. The only thing I could not use from the vette was the exhaust. I used edelbrock's chevy truck headers and they worked fine. The engine mounts were a direct bolt in, no adapters required. The engine bolted directly up to my 5 speed and I was able to use the entire stock clutch and flywheel off my original engine. Even the starter from my 92 V6 worked excellent for the LT1.

The LS2 is the new engine they are putting in the new 2004 Vettes. I am not too sure of the difference between the LS6 and the LS2 but the engines put out over 400 hp from the factory.