Rebuilding 350

[Xgreg27x]

I'm going to rebuild a 350 engine for my 1987 chevy V10 truck and I was wondering what options on pistons and cams I would need, I'm looking for decent power and torque. I got 2 engines to choose from to rebuild one is an older 350 casting is 3960010 4 bolt main and the other is still in the parts truck a got, I'm not sure what it is I can't get to the numbers on the back of the block because it's still in the truck and the pad on the passenger side in front of the block is blank looks to have been milled down, but it has after market world s/r i-052 heads on it. I haven't decided which one I'm going to use but I'm planning on using the s/r heads and getting a performer intake to fit a quadrajet. What pistons and cam should I use with these heads?

 

[1987 GMC Jimmy]

@rich weyand

 

[rich weyand]

Do you know what size chambers the heads have?

And which size valves?

What's the part number on the end of the heads?

http://www.pbm-erson.com/UserFiles/Documents/Product/Casting-Guide-World-Iron-Heads.pdf

 

[Xgreg27x]

42660 and I'm not sure about the valves it's still in the truck.

 

[rich weyand]

OK, that should be the 67cc chambers with the big valves. Nice.

That should be nominally a 9.3:1 compression ratio with stock pistons, but Chevy overstates them by about .5, building in some carbon buildup or something.

Anyway, those are probably the best heads of that series. Similar to the Dart heads. 400+hp/400+ftlb is a pretty good expectation there. You don't need to do the bottom end at all. Fancy pistons will just push you up into a compression ratio that will have trouble with pump gas. It will raise horsepower, but not torque, and with 400+/400+ you are at the raw edge of what the stock drivetrain will take anyway.

Here's some threads on cams with the Dart heads. You should be similar:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=28753.0
http://www.gmsquarebody.com/forum/showthread.php?t=10172
http://forum.73-87chevytrucks.com/smforum/index.php?topic=28581.15
http://www.gmsquarebody.com/forum/showthread.php?t=12108

 

[Xgreg27x]

What about cam and intake? Would the performer 2101 intake and an rv style cam work?

 

[rich weyand]

What about cam and intake? Would the performer 2101 intake and an rv style cam work?

As far as the cam, read the threads above! Everything you want to know is there. I've written it once already.

2101 fits the Qjet and will work fine. The 2601 will work a bit better in hot weather but *must* have a thermac air cleaner or it will suck big time in the cold.

 

[Xgreg27x]

As far as the cam, read the threads above! Everything you want to know is there. I've written it once already.

2101 fits the Qjet and will work fine. The 2601 will work a bit better in hot weather but *must* have a thermac air cleaner or it will suck big time in the cold.

The 2601 looks to sit higher I got a tg700r4 transmission in my truck does the added height affect the tv cable adjustments on the transmission?

 

[Xgreg27x]

Would the 12-238-2 cam work good for me?

 

[rich weyand]

Would the 12-238-2 cam work good for me?

Yes. That's one of your best picks, actually.

 

[Xgreg27x]

Would the 12-238-2 cam work good for me?

Thanks for all the information, does the 2101 intake fit the s/r i052 heads the description says it doesn't fit 1987 or later cast iron heads? Thanks again

 

[1987 GMC Jimmy]

The 2601 will work a bit better in hot weather but *must* have a thermac air cleaner or it will suck big time in the cold.

So does this mean you have to keep the heat riser tube, the manifold stove, and factory manifolds, or is there a way to have the full thermal air cleaner system with headers?

 

[rich weyand]

So does this mean you have to keep the heat riser tube, the manifold stove, and factory manifolds, or is there a way to have the full thermal air cleaner system with headers?

Funny you should ask that question:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=27239.0

 

[1987 GMC Jimmy]

Thanks for sharing. That's roughly what I imagined something like that would look like, but I haven't seen anyone do the air gap intake with headers before.

 

[rich weyand]

Yeah, I did the air-gap manifold first, but winter performance and mileage sucked, so I worked out how to mount a warm-air induction system on headers.

The air-gap with cold-air induction is your best-performing manifold in hot weather, because you get the densest charge. In the winter, you need to heat it to get carburetion working properly and prevent icing. But with a temp-isolated carb and runners, plus thermostatically controlled inlet air, you get great performance in all ambient conditions. This is the thing that lab testing of manifolds at room temperature will never show. When I start it in cold weather, it does the typical cold-engine rough idle nonsense for about two minutes. That's how long it takes the headers to heat up and warm the carb. At two minutes or so, the idle smooths out, regardless of how cold it is. It's a beautiful thing.

And if you put a chrome beanie on the air cleaner, and get an aftermarket cold-air induction tube, it comes out looking OK.

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