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Anyone have a GM Goodwrench 350?

44K views 27 replies 13 participants last post by  Plaintoast 
#1 ·
#2 ·
64 ss, - In addition to GM Goodwrench have you checked with Kragen to see what they have. A good friend bought a long block throught Kragen, here in San Diego, a few years back and has been overly pleased with his purchase. They offered several different builds (re horse power), depending on what you want. - Jim
 
#3 ·
your search link is broken now... my dad has the GM Goodwrench 260hp crate in his '72 C10.. bout 10k miles on it now.. decent, has a cam that's a bit small but a BN engine for $1799 Shipped, cant beat it.. 5/ 50k warranty cause it's installed in a Chevrolet 1972-1986
 
#9 ·
im not sure what your looking for exactly, if your going to fine with the 260hp they produce, and dont really care to get much more out of it that yes that motor will do fine, but if you want more performance out of it later on down the road then i would not suggest this motor at all, for one it is already slightly over camed for the heads, if i remember correctly the cam is an old corvete cam but the heads are stock low performance 76cc heads, the crompression ratio has been estimated at 8.5:1 but tests have shown it to be more around 7.9:1, these motors have been refered to as a left over parts on the shelf motor, the combo of parts just doesn't mix that well, the heads and compression wont support a stronger cam

in my personal opinion i would stay away from this motor, here is a link or a repitable engine builder with fair prices, and this is a much better canidate motor for a large vehttp://www.blueprintengines.com/popular_configurations/index.html?topic=specs&pc_id=93hicle such as the 64 impala
 
#11 ·
I too at one time bought a G.M. Target Master 350. IF I had to do it all over, and I only bought one due to "convienence", I would buy locally; despite the warrantee. The engine did not have many miles on it, but had been in the truck for several years, mostly sitting. It dropped #8 exhaust valve, and was past the warrantee. When I tore it down, the engine looked like it had 200K miles on it, the cylinder ridge was huge! I've heard the Target Master, "Hecho en Mexico" engines, are cast with very soft, cast iron. The ridge would seem to prove that. I still have the block, but have put off using it; sold the crank, rods, and new pistons I bought to rebuild it. I've become more of a believer in supporting my local economy. That's my stand, and I'm sticking to it.
 
#13 ·
junior stocker said:
I too at one time bought a G.M. Target Master 350. IF I had to do it all over, and I only bought one due to "convienence", I would buy locally; despite the warrantee. The engine did not have many miles on it, but had been in the truck for several years, mostly sitting. It dropped #8 exhaust valve, and was past the warrantee. When I tore it down, the engine looked like it had 200K miles on it, the cylinder ridge was huge! I've heard the Target Master, "Hecho en Mexico" engines, are cast with very soft, cast iron. The ridge would seem to prove that. I still have the block, but have put off using it; sold the crank, rods, and new pistons I bought to rebuild it. I've become more of a believer in supporting my local economy. That's my stand, and I'm sticking to it.
i also agree with this you should have a local machine shop that could help you and you could get exactly what you want, i still stick with what i said about this motor it is a combonation of parts that gm had sitting on the shelf and decieded to put them together for a budget 350, i have heard a lot more bad about these motors than good, i still wouldn't up-grade the cam in it, unless your going to upgrade the heads as well
 
#14 ·
have had bad luck with our goodwrench 350 we bought brand new from the dealer for the 82 k10

it burns oil and it leaks oil out all the lower seals including the RMS

plus they are crappy mexican ligt cfasting garbage

i dont know why he bought it for

dumb.

i always spend the $ and rebuild an original casting 350


way less money and many times better by far

just my experience

1300 or 1700 is freaking insane

stupid..

good luck
 
#15 ·
I currently have a gm goodwrench 350 crate motor. It has 8k miles on it an no problems other than the guy I bought it from put a offy tri-power set up on it and it's too much for the motor. While it hasn't given me any problems I have to agree with the other posts that you would need to be happy w/250 or so HP without doing a lot or work. I have it in a '32 ford and the nostalgic look w/no power is driving me crazy.
 
#16 ·
64_ss said:

this is still just my opinion, i saw the discription, and the motor is already bored to 4.060 which leave pretty much no room for a later rebuild if nessisary, i would hope since it is a 4.060 bore it should be a standard gm production block that used to be a core, that part is good, i would still say that the heads are garbage and it is over cam'd for the heads, once you get all your pulleys/brackets/carb/intake/distibutor etc-etc you will have 3k+ into it, IMHO i would scower a junk yard for a pre-86' 350 complete motor, that way you still have all the accesorie brackets, crank, and rods, take it to a machine shop and have them rebuild it for you, once the whole thing is said and done you will have a 355 built with exactly what you wanted, by someone in you home town with what i garrentee you more power than you would get from this place for pretty much the same money
 
#17 ·
Why do you think the heads are garbage, what head would you reccomend? The only thing im buying new would be the carb, intake, distributor and everything else im taking off my 305 and would apply it to the 350. This shop" http://high-performance-engines.com/index.shtml " is only about an hr away from me.

I do have a 66 327 its rated at 220hp it came out of a 66 truck sitting in the garage that needs to be redone. But i dont know if its going to cost more to get the desired hp/torque that id like, than just buy a 350 long block?

Im going to put it in my 64 impala with a 2 speed powerglide.

my87Z said:
this is still just my opinion, i saw the discription, and the motor is already bored to 4.060 which leave pretty much no room for a later rebuild if nessisary, i would hope since it is a 4.060 bore it should be a standard gm production block that used to be a core, that part is good, i would still say that the heads are garbage and it is over cam'd for the heads, once you get all your pulleys/brackets/carb/intake/distibutor etc-etc you will have 3k+ into it, IMHO i would scower a junk yard for a pre-86' 350 complete motor, that way you still have all the accesorie brackets, crank, and rods, take it to a machine shop and have them rebuild it for you, once the whole thing is said and done you will have a 355 built with exactly what you wanted, by someone in you home town with what i garrentee you more power than you would get from this place for pretty much the same money
 
#18 ·
I took a look at the specs, and the cam duration of 278/288 at .050 for the 275 HP engine does not make sense. That duration is way too high for an engine this mild, so its probably not the right numbers.

If it was my choice (and not my money) I'd get the 350/351 hp Vortec engine from these guys. You get Vortec heads with decent flow, and a reasonable duration roller cam (220/224 @.050). This should be a very good power combo now, and if you want to get more HP later you have a better base to work from (better heads and a roller cam).

Bruce
 
#19 ·
This place will also build one to your specs. What would yall recommend for a 350 (cam,heads,bore). All im really looking for is a strong running motor, i dont plan on racing or anything, just something to get my car moving. Im guessing 300hp with good torque is what i need but i dont know. That's what im on here for trying to get some input.

Tomorrow im going to call a local machine shop and see what they can do.
 
#20 ·
when i said the heads were garbage, i saw the specs and saw the cam then the hp/tq output an just what the previous poster said it doesn't make sense, they either made a typo, or those heads flow like crap, which honestly i would say the heads flow like crap, you heads will seriously depict how much power your motor makes

i would look for a 350 with no more than a .030 over bore, that way it could still be safely bored again, vortec heads, they are something that gm got very right, with the heavy full size car that you have i might even look into building a 383, it would cost pretty much the same as building a 350, but you get a slight hp increase but the real advantage is you get a nice tq increase at a lower rpm typicaly, cant recomend cam cause i would need to know more about the car, trans, gears, size tires, over all expected use, compression ration- bla, bla, bla
 
#21 ·
The Goodwrench blocks seem to be ok but the heads are really poor. I have a set of "made in mexico" heads in my garage and they look terrible. Super small exhaust ports that are not even where they need to be (core shift). Plus my buddy is having engine over heating issues with a gm 350 crate that may or may not be linked to the 350 goodwrench block (still working on that one). But we plan to change the block this fall to find out.

I would go to your local junk yard and get a complete vortec 350 engine with roller cam. Get a complete engine from fan to flywheel. And while you are at it, get the transmission too. Could even use the stock efi system if you get the computer and wiring. Otherwise a votec intake and holley carb with do the job.


Super Chevy (October 2009 issue) did a 407hp/410ftlb 350 build for $1155.00. And that included the used roller short block. But this engine would need a stall converter and gears (more of a street/strip engine). But could be setup with less cam to make 350hp and a nice daily driver.

In your case, just a shock rebuild on a 350 vortec will make 280hp with a set of headers. 325hp+ with a mild roller cam.

In any case, the biggest performance gain will be to junk the 2 speed transmission and install a 3 speed or 4 speed.

Should be able to get the old 327 rebuilt with a mild cam and assembled for less than $1500 (9.0:1 cr, compcam 260H, 300hp/325ftlb). Then use a th350 trans for a lot more acceleration.
 
#23 ·
64_ss said:
I had a guy give me a set of double hump heads awhile back, they were originally 1.94, but he had the intake changed to 2.02. Are these heads any good since he modified them?

what is the serial number on the heads, 2.02 valves in most heads wont hurt anything and in most will help flow on the intake side, but what is the serial number as gm made many "double hump" heads some are better than others but if they are real double humps then they would certainly be better than a set of heads of the two motors that your looking at
 
#24 ·
Casting# 3890462



my87Z said:
what is the serial number on the heads, 2.02 valves in most heads wont hurt anything and in most will help flow on the intake side, but what is the serial number as gm made many "double hump" heads some are better than others but if they are real double humps then they would certainly be better than a set of heads of the two motors that your looking at
 
#25 ·
He gave them to me because he had about 3 or 4
sets already, he said they weren't cracked or anything.
Maybe I should just get my 327 redone and put these heads on it.
What kind of setup on the 327 could get me at least 300hp and good torque.
Btw how much does magnaflux usually run.
 
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