I have a 91 RS with a stock 3.1 liter engine. It's not so bad, really. I put in posi from an older trans am, took the air cleaner from a tpi engine and stuck that on the front. And I've been replacing stuff with performance parts as I go.

Lately though, I decided against the advice of a rice-burning friend that I desperately need to a pack a 350 under the hood. He says that I could more effectively add horsepower for less money by installing a turbo and stuff like that. I am one to believe in big, shiny, full-engine power. So after searching for a while I found Carolina Machine Shop (i live in SC) where they have good completely remanufactured chevy 350s.

My question is, would I be better off investing in a remanufactured, bone-stock 350 from there, or would buying a used but running engine and rebuilding it (maybe new camshaft/reman heads) be the better way to go? I know the latter is definitely cheaper, which is attractive, but which would honestly be the best way in terms of longevity/performance?

 

If money isn't an issue, you can get crate motors that are professionally built from all new parts, it's by far the easiest route especially when you look at how long it will take to build your own given machine work and assembly time and general research. GM performance parts crate engines seem to be a popular choice, especially the budget flat tappet engine, the 330hp h.o. and the l31 roller cam engine. An all new crate engine would be very hard to beat in terms of longevity. As far as performance, that's all about money, not so much where the engine came from and in that case, you can probably manage more bang for your buck with your own build.

 

Go to CMS, and talk to them face-to-face. They can probably do you a 350 short-block (no heads) with flat top pistons, in an '87-up block, for around $1000. This is a great way to start. If they can do that, they should also be able to do you a 383 stroker for about $500 more. If so, ask about using pistons with a 12cc dish. That's one of the best ways to start. Then contact www.competitionproducts.com and spend $575 for a bare pair of Patriot Freedom 185cc/64cc heads, and another $80 for a set of stainless 1-piece valves. That's the best bang-for-the-buck whether you go 350 or 383. Hold off on springs and retainers until you choose a cam. And before choosing that, we need more info. How important to you is gas mileage? What percentage of the car's use will be in stop and go traffic, and what percent out on the open highway? Do you want a smooth idle or a race-car-sounding idle?

 

Well I wanna stick with a 350 partially because it is a daily driver and partially because there's just so much you can do with a really common engine like the 350. I spend the majority of my time highway driving so stop and go isn't much of a problem. I'm pretty used to a rough idle. For no particular reason my engine rocks around a good bit and I like engines that sound aggressive because they just are, not because of the exhaust.

Money is a bit of a problem in the way that I'd like the engine to stay around 2500 or so. A custom build is what I wanted but I've never done it and my dad's not as into the idea. but there is something attractive about a cheap, but usable block and dumping the other cash into performance stuff. I don't know much about cams or anything because I've never tore further into the engine than the injectors and mess.

 

Now you have to make a choice. Either an aggressive-sounding idle, or good on the highway. This is an either-or thing, you can't really have it both ways. An LSx swap would get you closer, but that's not in your $2500 budget. the cam for lots of highway driving will not give you an aggressive idle, and the cam for an aggressive idle is gonna suck on the highway. If you want the idle, get COMP's smallest Thumpr, while if you want best highway, get COMP's second-smallest XFI. That'll get you to 375 HP at around 5500 rpm, and over 20 mpg with proper gearing, while the Thumpr will exceed 400 HP up around 6000 rpm, but forget about gas mileage, it'll be low teens.

 

Hmmm. I guess all in all, considering there's nowhere to really race or anything, gas mileage and a good smooth idle would be the best way... all i really know is that I was disappointed in seeing that putting in a stock 350 would not bump me up to at least 275hp without having to upgrade a bit. oh well. so yeah, i've found a few that are suitable engines for my price-range, but I was wondering if anyone knew of anything better or what

 

Keep in mind folks, his budget is $2500. That's NOT motor budget, that's total budget - he's gonna need a tranny as well, since he's a 6cyl at the moment.

Now - guess it just depends on what you find. I got my 350 for $600, that was carb to oil pan, already built and run. It's a 1969 block = nothing fancy, has 70's smog heads on it, and 10:1 dometop pistons to help the larger chamber smog heads. But, coming from a 305 TBI to this old 350 was like night and day - so going from 6banger to any 350 is gonna be wild for you! And, any 350 can be updated later with better heads, intake, exhaust, etc. And I've been driving it almost 3 years now with no problems what-so-ever.

So, it doesn't have to be new pretty crate motor, or anything expensive - just a good used 350 will give you a great foundation to slowly build on over the years. Especially since you're gonna need a tranny as well.

 

This is where I'm confused, though. I've been told by a lot of people including the tranny shop that rebuilt my 700r4 (my dad and I are generally DIY but never been good at transmissions) that the tranny should swap on over. I have a feeling that being that it's set to handle a 6 cylinder the tranny may need to be beefed up a little.

 

It's my understanding that the V6 trannies have a different bellhousing. And that they wouldn't handle the power.

When I swapped my 305 V8 for the 350, my tranny was fine, or so I thought - the 305 didn't have the power to let me know the tranny was slipping - but the 350 surely did, the first day! Needless to say, I had to take tranny out and have it rebuilt before I could even test drive the 350.

 

Yeah I did some major research. appears you are correct! especially about the bell housing. Now i'm on a search for a cheap transmission... I'm getting an early 80's engine so an 84 tranny would fit that. still... not cool

 

A $2500 budget for the engine is realistic, but if that money has to include transmission, exhaust, ans such, then you're looking at a $150 engine from Pick-N-Pull. If you're going for a 700R-4, get an '87-'92 version. The '84 version is the 27 spline input, among all the other problems with pre-'87 700R-4s.

 

Times 2. And you may as well get a 350 from the same years with the roller cam, one piece rear seal (and the flexplate). Pull it from a car with front end damage so at least you know the car was moving forward the last time it was on the road.

 

I forgot to mention that I wanted to go carbureted. I was told to effectively do that I wanted a block that pre-dates '85. There is a camaro/firebird yard that often has parts, but they're often in such a state that it takes a ton of work just to get the parts in shape to use. everyone seems to either blow out the engine or transmission or mangle the whole car in some kind of catastrophe. I was looking on ebay and there's a place selling transmissions for like 600. might check them out

 

the '87-up blocks are still the preferred choice, carbureted or injected. And with these blocks, identification is easy. First, the 1-piece rear main seal's aluminum housing is easy to see. Second, the 350s have "5.7LG" cast right where the regular casting number is, behingd the driver's-side head, on the bellhousing flange. 95% of these blocks are in fullsize pickups, but before you leave the yard with your truck 350, remove the intake and heads, then find an '87-up passenger car 305 to get the hydraulic roller lifters from. Also get the matching dogbones, spider and pushrods. It's easier to buy a new retaining plate than to pull the damper, oilpan, timing cover and timing set only to break your torx bit trying to remove the one on the car 305. Then if you can find some non-swirlport 305 heads in good condition, bolt those onto the 350, assuming the 350 has dished pistons. You should leave the yard with one complete, assembled engine that is a 350 short block fitted with roller lifters and non-swirl heads. This will cost you the exact same as if you just took either the 305 or 350, but it's an all-day proposition. Your out-the-gate cost should be under $200 including tax.

 

that price should include the motor mounts. Any 305 car versions will work.

 

As far as trannies goes - most small non-chain tranny shop will have access to a yard full of them, used, and in the $400 range for a 87+ 700R4. Now, they may be fine, they may go out in a month - but they should come with a 30 day warranty.

Then, if you talk to the guy that actually does the work at same tranny shop, more than likely he rebuilds trannies on the side - I don't know any tranny man that doesn't do a few a year on the side for under-the-table money to buy beer with. This is how I got my 700R4 rebuilt for $500, and built right!

So, assuming you can get into something like that, that's say $1000 in tranny, leaving $1500 for engine - that should yield you a used 350 long block with enough left over for mounts and such - it's tight, but do-able. And remember, Santa will be here soon too!

 

LOL. Hopefully santa weighs down his sleigh this year! Guess it's time to peruse the yards here. Thanks for the advice guys!

 

I read up on 305 heads. sounds like it'll boost compression, assuming i find the right heads, but I'll lose top-end power at around 5500 rpm. so that means that i'll have plenty of power but it'll come up short if i decide to drag down the highway in excess of 100... is it really better for me to keep 350 heads?

 

The '87-up truck 350 heads will run out of air before the non-swirl 305 heads will. '70s 350 heads will lose compression, and won't give you any more rpm than 305 heads, because both are rpm limited by the mediocre-flowing exhaust ports. Avoid 624-casted heads like the plague. They're guaranteed to crack if they haven't already.