Chevrolet Performance 350/290 Crate Engine

Hello everyone,

It has been a while since I have been on here. Unfortunately, my 1977 Chevrolet Caprice is still in the garage, because it began to leak antifreeze after I drove it about 4 miles round trip one day. It appears that the leak is coming from the back of the motor, against the firewall. I am in the process of taking the motor apart, because I decided that I didn't want to 'put a band aid on the motor' by just fixing the one problem; and knowing that almost everything on the motor is over 40 years old now, another issue could develop easily. While taking the motor apart, I found rust stains in the aluminum intake manifold, and what appears to be surface rust cylinder heads and inside the block after the water pump was removed. Also, the antifreeze that remained in the cooling system had a rust-like color to it. Most of the cooling system has been removed from the car at this point.

I am trying to explore my options at the moment. On the one hand, I have a stock motor with around 64K on it. I could take it apart, send it off for an acid bath, etc; but I am guessing that will probably be an expensive endeavor. On the other hand, I am considering just pulling the motor and replacing it with a crate motor. I was originally considering the GM Goodwrench base 350 SBC, swapping the camshaft for a little more power and a noticeable idle and adding an Edelbrock Performer intake manifold; but now, I am considering the Chevrolet Performance 350/290 SBC with an Edelbrock Performer intake manifold. Has anyone swapped the 350/290 in any of their vehicles (does not even have to be a B-Body), and can you tell me if the camshaft in the 350/290 crate motor has a noticeable idle, please? I tried to ask this question on a vendor's website, but the function for submitting the question was not working properly.

Thank you, in advance, for helping this fellow B-Body owner get back on the road...soon.

I'm in the same boat. I also have a pair of smallblocks in need of teardown and machining. I have mulled this same decision to an obsessive degree. My objective was to make a peppy, reliable cruiser capable of 75 mph on the freeway. I want to retain my factory trans and original gears. 2.56 I believe.
It appears that only difference between the goodwrench 350 and the 350/290 is the cam. The popular opinion is that the smog era heads still suffocate that motor, and the upgraded cam does little more than move the powerband higher into the rpm range. It retains the same low compression 76cc combustion chambers and pistons. Being that I like my torque down low to move me with the highway gears on the street, I decided that the goodwrench 350 would better suit my needs until the warranty expires. At that point i can cam it and go for a set of heads.
Another option is the L31 vortec crate motor. Vortec heads, 2 bolt mains (good enuff for me), roller cam. It has a lot of untapped potential for a few bucks more. Make note, it does not have provisions for a mechanical Fuel pump $. You'll need a electric fuel pump setup, flexplate, possibly a starter to match the setup. Very do-able.
I can't realy say whats best for you. I weighed my many options and starting going down the "for a few dollars more" rabbit hole and had to pull myself away. I like to cruise and get on it once in a while, without blowing it to hell. Im too poor and too spread out to make everything "awesome". I recently found the goodwrench for $1,750.00 shipped. When I added up everything from air cleaner to motor mounts, I was under $4,000 for the goodwrench swap.
My buddy with connections in the machine and speed shop said he couldn't come close to that price to work with what I have and still have no warranty.

The $1,750 deal was from radley gm wholesale, but it seems the price has gone up to $1,825. Its available through amazon and dirct from radley. I'd bet they would take your offer for $1750. Couldn't hurt to ask, if you go that route.
Let me know what you decide on.

Any update to this ? ? ?

The Goodwrench 350/290 is a very good choice for both of your applications. You need to remember that your original engines put out no where close to this amount of horsepower or torque. As for a cam if you want to go ahead and say screw the warranty then call comp cams and they can reccommend the best cam for your own setup. I did this years ago for my 82 Impala and the difference between the stock motor and the goodwrench motor was huge. I am a auto tech by trade and have since gone through the engine and made many changes but this is a great start for a budget build.

If I was purchasing a bone stock motor, I'd get a Comp Cams 12-211-2 sbc Chevy Magnum 270h Cam Camshaft 350 383 Mild Idle.

Purchase some new performance hydraulic lifters to go with it.

Check out Ebay and see.  If its a flat tappet its great.  Nice strong and moderate idle.

I blew both of the headgaskets in my original l03, I drove it like that for an unknown amount of time and started blowing starters left right and center. (lifetime warranty at Oreilly and the boys there never asked questions ) Anyways realized the blown and cracked inhalf starters were caused by my cylinders being hydro locked which was inturn caused by the blown head gaskets.. A buddy let me use his shop and I pulled the accesory drive, radiator, waterpump, distributor, intake and heads within a few hours.. (at the time this was the biggest job I had taken on) Anyways, splashed the heads in acid for $50 bucks, got a gasket set for maybe $60 bucks and planed the heads myself :O All in all I was out maybe $150-$200, the reassembly took maybe 6 hours and the 305 purred like a kitten after that for many more years! Until I dropped a 383 in it back in the year fourteen. A motor with only 65k is imho worth saving, my 305 was pushing 250k when I pulled it and it was still strong. So, it may be worth sticking with your current powerplant until you have mapped out exactly what you want to repower with.. I did my repower for under 4k as I was on a budget, I think I got the long block for 2500.. However, since then I have had to upgrade all the sattelite components that are easy to forget about, High output alternator, fuel pump, race starter, flex plate, assembly drive ect. So, if your looking at making a significant jump in power and displacement there are those "hidden" cost to consider..

Also, just throwing some nice heads, exhaust and a cam can really make a stock motor into something far from average, If I had had a 350 instead of the 305 that would have been my route.