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monzter 05-31-2009 07:44 PM

Couple Of Questions - 350 Chevy for a Jeep
 
Hereīs the thing guys, I own a Jeep Wrangler Yj 1987 on 38" tires with 4.10 gears, it has a Chevy 350 from a 1973 Chevy C-10 and is probably around 150 horsepower, it has a Edelbrock Torker Intake manifold and a 4 barrel holley 600 cfm carburetor, i am assuming the heads are stock with probably 1.72" Intake valves and also that the camshaft is a stock one. There are headers on the engine. The transmission is TH-350 with shift kit and i assume the converter is stock one and the transfer case is dana 20.

So hereīs the thing, i have in the garage slightly massaged 3932-441 gm heads with 1.94" Intake valves and a thinner 0.015" head gaskets to bump the compression up a bit, I also have the Crane Powermax 272/284 - .454"/.480" lift ( 216/228 @ .50" ) Camshaft on 112 Lsa that i am thinking about to put in the engine, the ignition is a slightly modified Gm HEI.

How do you guys think this would work out, It would be grate if this would get me around 250+ horsepower for my Jeep.

Best Regards

monzter 06-01-2009 06:56 AM

And i forgot to mention that i am going to use it on trials and in mud, if that matters :)

Best Regards.

oldbogie 06-01-2009 12:25 PM

Quote:

Originally Posted by monzter
Here?s the thing guys, I own a Jeep Wrangler Yj 1987 on 38" tires with 4.10 gears, it has a Chevy 350 from a 1973 Chevy C-10 and is probably around 150 horsepower, it has a Edelbrock Torker Intake manifold and a 4 barrel holley 600 cfm carburetor, i am assuming the heads are stock with probably 1.72" Intake valves and also that the camshaft is a stock one. There are headers on the engine. The transmission is TH-350 with shift kit and i assume the converter is stock one and the transfer case is dana 20.

So here?s the thing, i have in the garage slightly massaged 3932-441 gm heads with 1.94" Intake valves and a thinner 0.015" head gaskets to bump the compression up a bit, I also have the Crane Powermax 272/284 - .454"/.480" lift ( 216/228 @ .50" ) Camshaft on 112 Lsa that i am thinking about to put in the engine, the ignition is a slightly modified Gm HEI.

How do you guys think this would work out, It would be grate if this would get me around 250+ horsepower for my Jeep.

Best Regards

You need to look and see what heads are on the engine, it is unlikely that a stock 350 has heads with 1.72 intakes.

The 441s are no improvement over stock 78 heads, they are large chamber low compression heads with the added disadvantage of not having hardened valve seats for unleaded fuels.

Bogie

Plaintoast 06-01-2009 12:47 PM

Quote:

Originally Posted by oldbogie
You need to look and see what heads are on the engine, it is unlikely that a stock 350 has heads with 1.72 intakes.

The 441s are no improvement over stock 78 heads, they are large chamber low compression heads with the added disadvantage of not having hardened valve seats for unleaded fuels.

Bogie

lots of trucks came with casting 991 heads which was a 1.72 intake valve. there are other castings that did too, but thats a very common one.

but i agree, he needs to see what he has first to decide if it's an upgrade to put the 441's on or not.

my87Z 06-01-2009 02:14 PM

he also need to find out where the piston is at TDC before he goes committing to a specific head gasket thickness, using a thinner head gasket to get higher compression is the least advised method as it changes your quench, which you will want to be around .036-.045

my87Z 06-01-2009 02:18 PM

**I also have the Crane Powermax 272/284 - .454"/.480" lift ( 216/228 @ .50" ) Camshaft on 112 Lsa that i am thinking about to put in the engine, the **

this is a pretty healthy cam for muddin' where you want the brunt of your tq to be made by 3k, this is just my opinion but i might look at the mega 262 or a cam in that range, fi used with a good match of top end parts this cam is very capable of 380+tq

cobalt327 06-01-2009 04:20 PM

Quote:

Originally Posted by Plaintoast
lots of trucks came with casting 991 heads which was a 1.72 intake valve. there are other castings that did too, but thats a very common one.

Indeed there were- like to have fell out when I pulled the 350 SBC from a ca. '77 Blazer and found 1.72" intakes and 3/8" stem 1.5" exhaust valves- what you might expect to see on a 20-30 Series truck. I don't recall the c/n, darn it!

This engine seemed to be the original to the Blazer- had never-removed exhaust manifold bolt locking tabs, the OEM thread lock still on the bolts that hadn't been removed before, all original ground straps everywhere, etc.

Found this HERE:

1971-77 heads w/casting numbers that end in 882, 993, 487, 336 can have the 3/8" exhaust stems. 20-30 Series truck use.

Both small 1.72" intake and 3/8" stem exhaust valve on c/n's 261, 624 (likely one of these was on the Blazer I worked on).

Also 1987-'95 center bolt v-cover-type head c/n 14102191 can have the 3/8" exhaust valve.

EDIT- This could be a good engine to use the Vortec head on- it does require a different intake, but since you're already using a poor intake (IMO) an intake swap would help in any case.

There are $140 (new) intakes available for the Vortec heads from Professional Products, heads cost about $150 used (give or take), require some inexpensive mods to use w/lifts over .450" or so.

You can do a search on this forum for more info on the Vortec swap.

F-BIRD'88 06-01-2009 04:52 PM

Find some #416 305 heads and give them a good home porting.
A ++ would be to have larger 1.94 intake valves installed (valve job)
Install them with your .015" head gaskets.
Your Crane cam will work well with these heads on a 350.
Find youself a dual plane "RPM" hi rise manifold.
Sell or trade the 441's for #416's, or 083's or other cylinder heads with smaller 58-64cc combustion chambers.

You'll get a good increase in engine compression ratio, torque and horsepower by making these changes.

monzter 06-01-2009 07:43 PM

I donīt want to spend any money on this engine ( or as little as possible ) Because i am building another engine that is going to be much more powerful than the one i have right now ( but thatīs another story )
But those parts that i mentioned above are parts that i already have in the garage and thought it might be fun to throw in the engine that is already in the Jeep, just so i would get a little seat to the pantīs feel :D

Best Regards

my87Z 06-01-2009 07:53 PM

Quote:

Originally Posted by monzter
I donīt want to spend any money on this engine ( or as little as possible ) Because i am building another engine that is going to be much more powerful than the one i have right now ( but thatīs another story )
But those parts that i mentioned above are parts that i already have in the garage and thought it might be fun to throw in the engine that is already in the Jeep, just so i would get a little seat to the pantīs feel :D

Best Regards

sounds decent, i dont know what your piston and deck clearance is, the best/only way to tell is to pull the heads off and check with a set of feeler guages (cheap mans way) i would be a little weirry about putting in that .015 head gasket, you need about .040 between the piston (@tdc) and the head other wise at higher rpms you piston can smack your head or your vavles, and that is a dissaster waiting to happen

if your piston is .020-.025 below deck then the .015 gasket is good, any less and you'd better go with a thicker gasket, if your looking to get higher compression out of this have the heads milled by then you need to make sure that you have enough valve to piston clearance

monzter 06-07-2009 03:39 PM

What can you guys say about the Powermax 272 Cam, do you think it will do ok for my application or would you recommend anything else ?


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