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305 heads on a 350?

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Old 02-13-2018, 09:49 AM   #1
Dusky
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Default 305 heads on a 350?

Hi guys!
Took the valve covers of my 350 goodwrench crate today. Its supposed to be a 350 with less than 10k miles anyway http://smclassiccars.com/chevrolet/138973-1979-silver-anniversary-edition-corvette-priced-to-move.html

​​​​​​The head casting number is 14014416 ( OR 14g1448 OR b) but im guessing its the first one as thats the only one I could find online.
im guessing that this goodwrench crate never came with those heads? Are they good heads?
The block casting n is 10066036 so it has to be 350 right?
Are cams stamped on sbc's? On the engines I've worked on before the cam was always stamped at the timing gear end. Im planing on changing the timing gears anyway as I've heard theyre nylon, and a replacement set only costs 20$. Would be Nice to figure out what cam it is too then, the engine has me clueless.
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Old 02-13-2018, 11:48 AM   #2
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The block is from one of the Mexican cast/built GM Crate engines.

The heads are from a 305HO.

Looks like someone put those heads on a GMPP 290 crate in an attempt to gain some compression. Which will work fine at lower power levels... above about 350HP or so the small runner and valves will become a big restriction.

If it's an aftermarket cam it should have some identifying marks engraved or stamped on the nose under the cam timing gear. The stock cam will just have a SN for the core stamped on the rear face.
Will
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Old 02-13-2018, 04:21 PM   #3
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Cheers!
Guess I'll find out what cam it is soon then
Any ideas on the possible power gain of those heads? I mean, if it had 350 I would be very glad, even with 250 I wouldve been glad, considering its a L48 1979...
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Old 02-13-2018, 09:07 PM   #4
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It is very tough to guess because you are basically trading airflow for compression.... althou those heads flow about as well as the stock smoggers that come on GMPP 290 Crates. Without cam change all it would do is pick up the mid range TQ and make the engine feel more responsive.

Back in the mid 1990s we expirimented with those 305HO heads on limited oval track engines.... unmolested 041, 461, 462, 186 double hump small chamber factory high performance cyl heads were becoming difficult and expensive to get for those builds.... those engine made low 400 hp range back then, we equalled the power using the 305 HO castings but we had to cheat them up a lot more than the double humps and they would not make power to the same RPM.... we had bowl cut and acid ported them so thin that they would crack very easily if run hot. Luckily the production Vortec heads came about and we made more power cheaper.

My advice to you would be scrap the 305 heads, buy something else with more potential.
Will
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Old 02-14-2018, 05:15 PM   #5
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As the story goes, you take the drivers side cyl head and chain it to the aft of your pontoon boat. Then you take the passenger side head and chain it to the bow of the boat.
(unless you live in Austrailia, then its reversed)


Whole lot better stuff out there for sale.

Last edited by HeadsU.P.; 02-14-2018 at 05:31 PM.
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Old 02-14-2018, 07:01 PM   #6
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Better get a freight container to ship Them to Belgium though 😅
i bought this corvette thinking it had just a stock l48,so anything over that is a win. Mind, there isnt a lot of competition around here. Mostly youngsters in corsa's and MK3 golfs.
Though, are there any stock heads to look out for? Vortecs probably,but need a new intake with those too iirc, wich I dont know if it fits under a C3 Hood. And no means to test, my front clip is sitting next tot the car atm
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Old 02-14-2018, 08:25 PM   #7
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I don't know your budget and if you did find anything decent on EBay or CraigsList they would not get involved with shpg to Europe.
What is Summits and Jegs policy on foreign shpg? Likely cost an arm & a leg. I just hate to see you sink a lot of money into antique performing heads. For example:
Valve grinding, new guides, new seals, springs, retainers, splitlocks, a clean-up surface shave, would run hundreds & hundreds of $$$$. Can buy new heads for under $7 US bills.

Last edited by HeadsU.P.; 02-14-2018 at 08:27 PM.
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Old 02-17-2018, 04:40 PM   #8
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Quote:
Originally Posted by rklessdriver View Post
The block is from one of the Mexican cast/built GM Crate engines.

The heads are from a 305HO.

Looks like someone put those heads on a GMPP 290 crate in an attempt to gain some compression. Which will work fine at lower power levels... above about 350HP or so the small runner and valves will become a big restriction.

If it's an aftermarket cam it should have some identifying marks engraved or stamped on the nose under the cam timing gear. The stock cam will just have a SN for the core stamped on the rear face.
Will
Mexico? oh, I remember those now.. TARGETMASTER engines... translation.. junk
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Old 02-17-2018, 08:59 PM   #9
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Quote:
Originally Posted by HeadsU.P. View Post
I don't know your budget and if you did find anything decent on EBay or CraigsList they would not get involved with shpg to Europe.
What is Summits and Jegs policy on foreign shpg? Likely cost an arm & a leg. I just hate to see you sink a lot of money into antique performing heads. For example:
Valve grinding, new guides, new seals, springs, retainers, splitlocks, a clean-up surface shave, would run hundreds & hundreds of $$$$. Can buy new heads for under $7 US bills.
The heads seem quite well atm, seals etc look brand new, so Ill probably we just keeping them. Im intrested in performance, but I wont be spending big bucks on it (yet), still illegal to put different cams in etc too.. a lot like CA laws sadly.

​​​​​​Shipping from summit isnt too Bad, around 100$ + 30% import costs. If you place 1 big order its fine
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Originally Posted by fishslayer143 View Post
Mexico? oh, I remember those now.. TARGETMASTER engines... translation.. junk
you know the drill, you have to say why you say that too. Explain it to the poor European guy who could only dream of living in a Country where you can buy engines over the counter :p
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Old 02-17-2018, 09:13 PM   #10
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Quote

you know the drill, you have to say why you say that too. Explain it to the poor European guy who could only dream of living in a Country where you can buy engines over the counter :p[/QUOTE]

OK, Target Master was a Mexican cast block with sub par components, usually unequally sized journals on cranks. some were recycled Failure engines or their components . Assembled by low skilled $2/hr labor , originally Designed for cheapo replacement crate engines for fleet service trucks . just a cheap fix to get more service out of them.. low compression, low power , low reliability... ever take one apart? if so, you know what I m saying.. and as to why European guys cant get GOOD QUALITY engines... ITS CALL FREIGHT ... Vendors SHIP any engine you want.. to any country in Europe.. BTW, I lived in France and was born in GERMANY.. just sayin
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Old 02-18-2018, 07:22 AM   #11
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Quote:
Originally Posted by fishslayer143 View Post
Quote

you know the drill, you have to say why you say that too. Explain it to the poor European guy who could only dream of living in a Country where you can buy engines over the counter :p
OK, Target Master was a Mexican cast block with sub par components, usually unequally sized journals on cranks. some were recycled Failure engines or their components . Assembled by low skilled $2/hr labor , originally Designed for cheapo replacement crate engines for fleet service trucks . just a cheap fix to get more service out of them.. low compression, low power , low reliability... ever take one apart? if so, you know what I m saying.. and as to why European guys cant get GOOD QUALITY engines... ITS CALL FREIGHT ... Vendors SHIP any engine you want.. to any country in Europe.. BTW, I lived in France and was born in GERMANY.. just sayin[/QUOTE]
i hate it when people get arrogant when they didnt Read properly. Over the counter. Freight shipping isnt over the counter.
Take summits 1600 euro base engine. Calculated shipping : 1.093,48 euro without tax. You see where I'm going with this.
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Old 02-18-2018, 08:03 AM   #12
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ok, the 416 head is apparently 58 cc chambers and 1.84 valves. this 290 crate engine probably came with 72 cc chamber heads. so you are probably 2 points better than stock, I would guess approaching 10:1. rule of thumg is you pick up 4% in power for every point of compression from 7 to 9. and 2% a point from 9 on up. meanwhile you lose a bit at high rpm's from the smaller ports and valves. so it'll probably be a better street driver and suffer a bit if you are trying to get under 13.8 ET. they are paid for and work. run 'em... BTW, there is a lot of info on those heads on the thirdgen site.
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Old 02-18-2018, 09:06 AM   #13
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Quote:
Originally Posted by Dusky View Post
OK, Target Master was a Mexican cast block with sub par components, usually unequally sized journals on cranks. some were recycled Failure engines or their components . Assembled by low skilled $2/hr labor , originally Designed for cheapo replacement crate engines for fleet service trucks . just a cheap fix to get more service out of them.. low compression, low power , low reliability... ever take one apart? if so, you know what I m saying.. and as to why European guys cant get GOOD QUALITY engines... ITS CALL FREIGHT ... Vendors SHIP any engine you want.. to any country in Europe.. BTW, I lived in France and was born in GERMANY.. just sayin
QUOTE i hate it when people get arrogant when they didnt Read properly. Over the counter. Freight shipping isnt over the counter.
Take summits 1600 euro base engine. Calculated shipping : 1.093,48 euro without tax. You see where I'm going with this.[/QUOTE]


First.. I hate when people assume because hes in Europe that hes poor .. not cool... first a C3 like his gets 10-12 mpg, - gas there is about $8 /gal for 87 octane.. premium is ridiculous. .car insurance for a V8 350ci car there is astronomical. . If he bought a gas guzzling Classic like this, I doubt hes poor..

2nd...in my orig post I NEVER RECOMENDED HE SHIP OR BUY ANYTHING..try reading it AGAIN.. { I hate when arrogant people don t read properly}... I simply stated I recall TARGET MASTER.. YOU INSISTED I defend that they are junk and then for some reason why he cant get new engines. .. I explained .. and suggested freight if he chose to buy. you don t like the explanation, that's fine..I don t care. . I have shipped Dana 44 Differentials and TH400 trans to friends in Switzerland .. it did not cause bankruptcy .. have a nice day

Last edited by fishslayer143; 02-18-2018 at 09:07 AM. Reason: spilled my coffee
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