I am swapping in a 350 Carb in place of my 305 TBI. I was fairly certain I was going to go with L31 cam swap/headswap. I decided to go to a local engine builder and he told me that he could build an engine that matched want I wanted. I was concerned about some of his recommendations though. he recommended the following:

1) Ditch the patriot performance vortec heads with 185 cc intake runners and go with the DART S/S heads with the 165 cc runners. He said I would be un happy with the low end performance with the larger runners (Engine is a street/ weekend cruiser engine and I want excellent LOW- MID power)

2) Stick with 1.94/1.5 vales, no need for bigger valves for my application

3) Don't go with anything bigger than a 600 cfm carb, recommends Holley

Now for the engine specs:

Reconditioned/ Seasoned 350 block bored to 355 (ADD $500 for new block)
Scat 3.480″ Cast Steel Crank
Scat 5.700″ I-Beam 4340 Connecting Rods
Cleveite 77 MS909P Main & CB663P Rod Bearings
PBM hypereutectic Pistons my choice on CR probably going with 10:1
Brass Freeze Plugs
Dart S/R 165cc Brand New Steel Cylinder Heads
3 Angle Pro Street Valve Job
Hi-Performance 7/16 Screw in Studs & Guide Plates
Comp xr276 cam 224/230 .502/.510 Hydraulic roller
Edelbrock Air Gap intake Manifold
MSD Distributor
ARP534-9701 Complete Engine Fastener Accessory Kit
AERC Chrome Tall Valve Covers w/Baffles For PCV & Vent
Felpro Gaskets
Balance, Blue Print and Engine Dyno
2yr/24000 mile warranty

I maybe missing a few things as his printer was experiencing technical difficulties, so this is what I wrote down as he was telling me.

He stated that he would internally balance the engine and the crankshaft would be balanced to .2 grams and believes it would be in the 350+ - 375 HP range, with excellent TQ

Price for complete engine
$3500

Would need Water Pump, Starter, Wires , Plugs, Serp off My old setup ETC...
Here is a link to his website

http://awesomeengines.biz/

 

I would think with that set up you would go with a 750cfm carb, that could just be me though. Also that's a little pricey, could you do any of the work besides machine work your self?

 

wow sounds like a nice set up. as for the carb you should be ok. im sure they will set it up for you if you want. i know that on a zz350 it is a 600cfm holley. they look loke they build a lot of engines. i was thinking about the vortec patriot heads myself. and i to am looking for the same hp that you are looking at. and that cam spec is the exact cam that comp cams said i should run. 110 lsa and a106 centerline. ill have to keep an eye on your build. i suppose that the 3500.00 includes everything on the engine minus the accessories and all. are they going to dyno it for you. i was thinking that that was a steep price till i priced just the heads. assebled is near 1000.00.

 

Yup it includes everything assembled( Flexplate/ Balancer) everything except accessories and strater, wires etc... they will set it up dyno tune it. . The engine seems like a pretty decent deal to me the other engine was 2250 shipped + $150 to upgrade heads+ $260 to up grade cam +$215 for manifold + $260 for Dizzy + 150 gaskets and bolts, shipping and Misc for a total of $3285 for the modified L31 (with me doing all the work Cam/ head swap etc..), plus I get a Dyno tune and 24K mile local warranty with the above motor for another $200.

I was mostly concerned with the heads, they seem weak and seem to flow poorly. He did show me how much air the engine could use and it was 500 and change at 100% and that is why he told me I did not need a bigger carb ( said most people way over carb). He told me that he get those heads (Dart S/S 165CC for about $680 a pair assembled). I was wondering if there is something in the same price range that makes better power. I also wanted to know what you thought about the 165CC intake runner.

 

The 600cfm carb should be just fine for a street 355.

 

Anyone have any opinions on the heads?
Dart S/S 165CC
With:
Cam Comp XR 276 224/230 @ 50 .502in/.510ex LS 110

 

Anyone have any opinions on the heads I am a little concerned about the flow numbers large combustion chambers and intake runners. Anything significantly better in the sub $850 range?

 

I think those heads are a good choice for the price and for what you want. Just make sure your intake ports are not too big for your compression and the amount of fuel you will be pushing, and you'll be happy with the power you will make. The guy who quoted your engine build was right in suggesting lessening the port volume because a little too small is better than a little too big, when it comes to port volume. You don't even need 165cc volume for the horsepower numbers you're expecting.

 

i know that david vizard has went with those heaads on several builds and said they are an excellent choise for street strip cars. usually got more hp with them over other combos. now that i have searched everywhere i cant really get a good answer on them.