87' 350 SBC Rebuild

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Jlisle

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Army
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Houston
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John
Truck Year
1987
Truck Model
R10
Engine Size
5.7L 350
Hey Folks, I purchased a 1987 R10 w/ original 350 SBC sitting at 86k miles. It's a single owner which was great to find in my opinion.

I've got a few leaks, primarily from the rear main seal and oil pan, but also evidence of oil seeping from all other locations they can.

So, I'm doing my first rebuild. I plan to keep her stock other than dual exhaust, headers, removing smog system, and swapping to electric fans.

Offer up any suggestions you may have, thank you!
 

Ricko1966

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c20
Engine Size
350
Make sure the pcv system us intact and functioning correctly. Sometimes people do not realize that pcv is important,and they will leak from everywhere if pcv is not functional or the engine is not vented in some fashion. You do know not all the smog stuff is bad? Some reduce emissions without hurting power,improve mpg,and reduce cylinder head temperature.And removing any of it is illegal anywhere in the United States. It's federal law,and in area where they don't inspect just means you probably won't get caught.
 

Jlisle

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1987
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R10
Engine Size
5.7L 350
Make sure the pcv system us intact and functioning correctly. Sometimes people do not realize that pcv is important,and they will leak from everywhere if pcv is not functional or the engine is not vented in some fashion.
Thank you. The plan right now is to replace the PCV valve when I replace the valve covers. I'm also running a vented oil cap on the drive side valve cover.
 

shovelbill80

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Bill
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1986
Truck Model
GMC Jimmy
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3095
Tbi...carb? What's the goal? Duals for cool...sound? X-pipe?
 

legend57

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Rob
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1976
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K20
Engine Size
400
In '87, the bottom end was good and stout with the 4-bolt caps. The top end was terrible, mostly for smog reasons and economy. The result was a meager 210hp and 300lb-ft of torque. With a few minor modifications, it is easy to increase both by ~100 points, without losing low end performance.

A few recommendations, IMHO:

This one is almost a must-do:
* I would recommend converting to a retro-fit roller cam. You'll then have ZERO worries about flattening a lobe during break-in. Peace of mind and an overall valvetrain improvement in performance and reliability.

These are optional, for more performance:
* Since you're removing the smog equipment and adding headers, I take it you're looking for a slight bump in HP and TQ. To support those mods you're making, I'd bump the cam to an RV level. Stock cams were very conservative for smog reasons. Also, the heads didn't flow for the same reasons. At a minimum, I'd do some head work to get them to flow better. They're cast iron, so not as easy to rework as aluminum, but it can be done. You can actually do it yourself and save some money. If you can afford a good set of aluminum, 180cc intake runner heads, you'll be much happier with the performance. Choose the CC combustion chamber size to give you 9-9.5:1, or so. And of course, a decent aluminum intake manifold would be a good match for the increased flow of the cam and heads.

With your headers and a good carb/efi, you should easily make 300+ HP and 400+ lb-ft.
 

peats

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72k5, 81c10 short step, 83k10 short fleet, 03 SSR. 25 chevy doodlebug
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k5 c10 k10 SSR doodlebug
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406 360 6.2 5.3 171
I'm confused as to why you would want to put electric fans on a mostly stock build. A good radiator and fan clutch setup should be perfectly fine.
 

Ricko1966

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350
87 would be LO5 engine it's already 9.5 to 1 compression. Everybody bad mouths the 193 heads that are on it. Those heads actually do a real good job under 4500 rpm. They are a primitive fast burn so the make more torque with less timing and get better mpg than 99% of other SBC heads.Those heads will like total timing down in the 28*-32* range. GM used them for a reason,torque down in the rpm range most people drive at and better mpg. Keep your cam small and those heads will work good for a mild build in a budget. Everybody bad mouths them,I like them for a cheap head that does what it's designed to do. I drove to Kansas City to buy a pair from @legopnuematic . The mpg difference between tbibtrucks and carb trucks is not just tHe TBI it's also the heads
 

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