Aftwe wrecking my Bronco a few weeks back, I've been looking for another vehicle. The darn Bronco kept me so safe I wanted another one of those despite the gas footage, but I may switch over to the dark side having seen this one. I'm looking into a '92 Buick Roadmaster with the 180hp 350. I'd like to know if that engine can ultimately be upgraded to LT/1 spec, or if the LT/1 is a unique block with unique attributes. If I can upgrade, what parts do I need? I imagine heads, cam, and intake at the least...any specifics? Are these parts obtainable? Also, what other parts are out there for these full-sizers?

 

not sure about the 92, but usually gm and chebby use different engines.

 

I believe any parts you could need to upgrade to an LS1 motor can be obtained from Summit Racing. check out www.summitracing.com and order their catalog. they sell everything, from the smallest stuff to the whole engine and driveline if you wanted to just drop something in.

 

A fullsized Chevy car with a 350 is going to get 13-15 mpg, the same as the Bronco.

Once you have to work on that GM, doing things like changing the fusible links that are placed on the starter where it is hard to get at and almost impossible to splice in new ones, will make any Ford repair look easy.

I just finished doing them on my own Chevy and have done them on other Chevy vehicles including mini-vans. It is always a frustrating job and it is always something you have to do. I have seen them blow just "because" and it leaves the vehicle 100% dead.

Replacing spark plugs that are UNDER the exhaust manifold with no room to change them without using a swivel or two. Even worse is the sheet metal shield and how the spark plug wires do not even last three years with moderate driving.

Put a "hot" motor into a car and you better get ready to change your starter every year because the exhaust will cook the starter relay, since it is not on the fender like a Ford.

On a Chevy memorize this acroynm "EPROM" because on Chevys up to 1996, this is an expensive common to fail part in the computer system.

Freeze plugs UNDER the motor mounts so you have to lift the end to change a freeze plug.

I keep thinking the guy that designed the Ford Probe drivetrain must have one time worked in the GM engineer division.

If it was not for Chevy, there would be a lot more mechanics out of work, that is for sure.

 

I have worked on some Chevys, they really didn't strike me as being that bad. Honestly. And according to the ******** road testers that drove the car (whose numbers are usually very much on the low side anyway), they got 15-17 in town and 24-26 on the highway. I usually drive for gas mileage and expect to best those figures; I bested the road testers' figures by about 2-3mpg in the Bronco, and that with 85% in town driving.

Anyway, as far as I have found out, the only inherant difference is in the mains; the Gen II LT/1 is a 4-bolt, the 180hp version is just a two bolt, otherwise it's just intake, ignition, and heads...does that sound about right?

 

Actually a Roadmaster with a 180hp 350 will get 25~28 mpg....... The big difference between the 180hp and the LT1 in the induction system. I believe the non LT1 is a throttle body injection setup where the LT1 is a tuned port setup.

 

This is a Ford site and rebocardo is entitled as we all are to our opinions. Having said that, early-mid 1990s GM rear wheel drive stuff is about as stout as (relatively) modern iron is going to get. Styling is a subjective matter, but they were ugly. We had "Roadmonsters" as executive cars and some of them are still in the motor pool for us to use and they still run well. Motor pool Ford cars simply did not last as long. Highway gas mileage is excellent, due in part to something like 2.56 final drive ratios. All GM 350 (5.7) engines by then were Chevy, the Buick, Olds and Pontiac 350's were long gone.

Jim

 

The LS1 and LT1 are fairly different engines. The LS was if I recall all aluminum and had some of the accessorie mounts cast into the block and I even think the block was a stress bearing memeber in the Vette and the Camaros. The LT1 was the hot engine for the Impala/Caprice, Roadmonster and mid range Camaros and Vettes. Parts for LS and LT are not easily interchangable.

The trick to an LT1 is the reverse flow cooling on the heads. Also they use a special water pump that is driven off the front of the camshaft, ie there is a hole in the timing cover. To change the Roadmonster into an LT1 would require a fair amount of work and I am not absolutely certain the blocks will mate to the heads and pump anyway. Probably just easier to buy an LT1 and swap it in. There are a fair number of aftermarket parts for the standard 350 so that is also an alternative but they are not an LT1. There are a fair number of aftermarket parts for the LT1 also.

They came in the 94-96 Impala SS/Caprice, some of the Roadmonsters, some Caddies and a lot of the Camaros and low end Vettes from those years. The ones in the Impala and Roadmonster and I think Caddy had iron heads, the others were usually Aluminum.

The Impala and Roadmonsters were very similar bodies and drive trains, many parts were interchangable. I loved my SS and would still drive it now except for a bozo in a motor home causing a 4 car pileup. Up til then my SS gave me about 120K of relatively trouble free miles, at least far less than my Fords. I now own a Lincoln which has already given me more tranny trouble than my SS ever did. And you want to talk about maintenance nightmare as far as space to work in, ha.

There are a couple good sites for the LT1, a google search should turn them up.

I owned a 96 Impala SS and was a member of NAISSO. It was a heavy car but it got surprisingly good mileage. It got an average of between 14(heavy traffic short trips hills) and 18mpg(some stop and go, mostly freeway) on my daily commute depending on where I commuted and how bad traffic was. On the highway you could easily get 24mpg if you kept it under 70. You have to have bad traffic or a heavy foot to get less than about 17mpg. My Lincoln barely does better and it is a lighter more modern technolgy car.

Overall I would say my SS was one of the better cars I have owned in over 30 years of driving and repairing my cars. I have bought 5 fords, 1 pontiac, 1 chebby, 3Datsun/Nissan, 1 Dodge. The Chebby was in the top 2 or 3 of my favorites as far as overall enjoyment and reliability was concerned.

The areas of pain with the LT1 cars was the Dexcool antifreeze(96 and newer?), loose intake bolts, sparkplugs and wires not lasting the magical 100K miles(marketing BS I think) maybe 80K or with my driving 5 years, and the tranny would go at about 100K. I lost a fuel pump at about 80K. Otherwise the SS was pretty routine as far as repairs and maybe a bit better than my average.

I was able to completely change and rewire my plugs without a lot of difficulty. Does take longer than some cars but not terrible. Some NAISSO members moaned about it but I did not find it especially difficult. As far as fusable links, I never knew where mine were, they never blew. Ditto the starter.

Look for a Roadmonster with the LT1 already installed. The sure clue is that the waterpump is NOT BELT DRIVEN and there is no mechanical fan.

Al lot of the Police Caprice Cruisers are on sale and most have LT1s in them.

There is a mini LT1 out there too. It is the V6 version and I think it even has the LT1 type cooling, I could be wrong.

From someone who owned one and likes to work on cars,

Jim Henderson

 

Jim,

Lots of info in there. Some, like the gas mileage and the reliability I knew, some, like the reverse flow cooling, was new to me. From what you said, I would have to agree that a Gen II swap or just regular 350 parts would have been the way to go. I have tried to look for some Gen II equipped cars, they just aren't around here. Even if I found one, they wouldn't fit my budget anyway. I have heard about the cop cars, but they are ridden hard and put away wet, and besides which I was hoping for the pillow ride of the Roadmaster, which I much prefer to the stiffer ride on vehicles prevalent today. The Roadmaster wasn't quite as advertised, though, so I think I'm going to pass on it. Thanks to all who have replied!