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Topic Review (Newest First)
06-23-2011 07:49 AM
eric32 Thanks again techinspector, also just as others stated on here that is a LT1 350 and they can be made with some good power but they don't have as much as options as gen 1 350 motors but even the factory heads can have some work done to them and with a mild cam can make some really good power. Good luck on your build.
06-22-2011 07:45 PM
$125. you pull it motor.

that appears to be an lt1 350 engine.from the dist. behind the waterpump.
06-22-2011 07:43 PM
$125. you pull it motor.

that appears to be an lt1 350 engine.from the dist. behind the waterpump.
06-22-2011 07:13 PM
06-22-2011 06:52 PM
techinspector1 Hello Tech thanks for your help much appreciated. If you got time can you show me the numbers with a highrise dual plane non air gap design.

1500 105 368
2000 150 394
2500 188 395
3000 237 415
3500 287 430
4000 325 427
4500 354 414
5000 367 386
5500 340 325
Peak volumetric efficiency 89.5% @4000
Peak BMEP 182.4 @ 3500

Keep in mind that this is a 9.1:1 motor with a very short cam.
06-22-2011 06:39 PM
Originally Posted by Jaiden2010
The heads are 10125320.
06-22-2011 06:34 PM
eric32 From what I found out on those head numbers if the source is right they are a Chevy LT 1 350 which is a gen 2 small block chevy with reverse cooling. LT 1-4 heads and top end stuff will not work on gen 1 style block. There is some differences in parts mainly the top half and water pump etc. LT's are good and there heads are similar to a vortec head and if I read right vortec heads was designed after the LT head design minus the reverse cooling. Maybe others will post some more info.
06-22-2011 05:49 PM
Jaiden2010 I have another $1000 from our taxes maybe can squeeze another $500. Ill bug the wife enough and she will want to shut me up.
06-22-2011 05:45 PM
eric32 Hey thanks Tehcinspector much appreciated. I went with a different intake for time being to help see if the minor issue I had before was caused by intake leak and it was not after all so its on there for now might step up to a bigger high rise next year but I am done for now. Just got the motor and everything else back in last week and after 6 weeks am a little burnt out for now. That gives a good idea for this guy on a decent street motor. What does it make on the dyno sim if its not to much with high rise dual plane by chance with everything else the same? Thanks guys. Hope this guy figures out what to do within his budget.
06-22-2011 05:43 PM
Jaiden2010 I found this today for $125 I pull. Not sure if it's a 305 or 350, I can't see the casting numbers on the block. The heads are 10125320. I have no idea if it runs, it's a as is deal. I am going to build a fresh motor, as long is not junk inside maybe this is a better bet. I found it under the hood of a 60's chevy. I don't plan on running any fuel injection/computer in my S-10. I am going to run a carb. I am not skilled in playing with wiring etc. The engine harness and computer is there however. The transmission is gone. The motor is just sitting in the engine bay. Here are some pics I took with my phone and emailed to myself so excuse the quality.
Somebody did a lot of work to this Suburban it has a late model instrument cluster, late model 5 lug disc brakes, late model tilt, ABS module/setup. Looks like they just never finished the engine install. all the wiring is unplugged as with some of the fuel rails/injectors are out. Unless it happened at the yard?
06-21-2011 05:43 PM
techinspector1 eric32 asked me to run a sim on his motor on a PM. I thought I may as well post it on here for everyone to see. This is a very mild 355 with 9.1:1 static compression ratio, low-rise intake manifold, 600 carb, ZZ4 cam installed straight up. He didn't tell me about the exhaust system, but I'm assuming 1 5/8" long-tube headers. Heads are RHS 180's which I factored down to 95%.
1500 109 382
2000 155 406
2500 193 405
3000 230 402
3500 275 412
4000 302 396
4500 316 369
5000 313 329
5500 290 276
Peak volumetric efficiency 86.3% @3500
Peak BMEP 174.8 @ 3500
Motor makes 400+ ft/lbs of torque from 1800 to 3800, right in the street driving range and should operate detonation-free on cat pea pump gas. Low-rise intake is a power killer. A change to a high-rise, dual-plane intake would add 51 horsepower and 24 ft/lbs of torque according to the DynoSim software.

There's just no getting around it, you have to get the carburetor up off the motor in order to make power. The over and under runner system on a low-rise, dual-plane intake just doesn't work well. On some motors, like the big 472 and 500 Cadillac, the runners were so screwed up that the mixture went uphill to get to the head ports. You can get around it with a single plane intake, but then you are stepping into another rev range for the motor (4000-8000), whereas the dual-plane works well from idle to 6000.
06-21-2011 04:21 PM
eric32 If your looking to replace your heads does as tech inspector said above and it may cost less then getting a set of new heads assembled but don't quote me on that as some machine shops prices vary.

The best route if your buying a complete new set of heads you can go RHS pro action 180cc intake runner heads and they come in 64 or 72cc combustion chamber and I just put a set on my engine with a gm zz4 roller cam and they are very nice heads and worth more then my old world heads ever where. Search all your options and do with what will work best but don't jump the gun and say well this for now you will only spend more in the wrong run.

Reason I say that is I have done the quick route and then regret not doing more and then ended up spending more then what I should have and would of been less if I did it right the first time. In short terms use your budget wisely and make it match good and you should be very happy with it.

Have fun with your build.
06-20-2011 07:28 PM
ap72 with machine work and a good basic rebuild kit your budget is gone, also you will need the springs recomended for the cam. The parts you have will get you over 300hp, BUT those heads are pretty bad. If you can afford getting something better it would help but a good set of heads will probably run you about a grand on top of your $1500 budget. Proper machine work and good pistons, bearings, gaskets, etc are NOT cheap.

Also, most s10 swap headers are 1.5" primary size, those cant support much more than about 350hp, good 1 3/4" headers run about $500, and they'll support a little over 500hp.
06-20-2011 06:57 PM
techinspector1 These pistons
This cam
L31 heads from a boneyard, casting # 12558062 or 10239906. Magnflux 'em for cracks. Fit new STOCK springs and seals. Make certain seals are fully seated on the guide boss by tapping them with a socket and small hammer. The stock springs will work well with the mild cam and will not pull the rocker studs out of the heads. Doesn't matter whether the heads have hard inserts in the exhaust or induction hardened seats, either way will work. Same casting, both styles flow the same. Give 'em a good valve job and otherwise leave 'em alone. Use the rail rockers that came on the heads stock.

Align-hone the main bearing bores in the block and cut the block decks for 9.015" block deck height, referenced off the main bearing bore so that you know the block deck height is equal on all four corners. This will insure that the heads sit level and flat on the deck and that the intake manifold will sit square to the heads with no gaps to cause an internal or external vacuum leak. Use GM head gasket #10105117. Static compression ratio will be 9.1:1 and squish will be 0.042". Use Edelbrock #7116 Performer RPM intake manifold. 600 carb is all you'll need.

Makes 365 hp @ 5000 rpm's with a double torque peak of 420 ft/lbs @3500 and 4000. Should make this power on crummy cat-pea pump gas without detonation.

Cam begins making power at 1200, so it's your call whether or not you need a looser converter. If I did anything at all with this combo, it would be a mild 2000 stall unit just so I didn't have to contend with the car creeping at stoplights.
06-20-2011 06:09 PM
Jaiden2010 I will buy a Vortec intake if need be, I have no problem with that. I also thought maybe I should spend the cash for aftermarket iron heads. I want the most bang for the buck. I could always downsize on the cam, they aren't very expensive. I plan on a stall converter. I am most concerned with what heads, and valve springs I will need but maybe I can avoid that with a little smaller cam.
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