GM Performance 10067353 - GM Performance 350 C.I.D. Base 195 HP Engine Assemblies

http://www.summitracing.com/parts/NAL-10067353

i have a Holley 300-110 - Holley Keith Dorton Signature Series Intake Manifolds paired with a holly 600cfm double pumper
and 1 5/8 inlet to 2.5 inch outlet flowtech heads they say that i should get roughly 260 hp i want to get her up to 400hp any advise would be great.

 

easiest way is 150 shot spray Else another way is just to throw a better set of heads on it with a MUCH larger cam than what comes in that thing. A bigger cam by itself could get closer to 50-60hp more but those heads will be a real restriction at that point. I dont know much on those motors, but appear to be some old iron smogger type head. 76cc chambers for low compression. Just not a platform for hp.

 

the crate engine comes with 76cc heads and what type of cam would you suggest?

 

To get this crate motor to produce 400hp you need to replace the cylinder heads, camshaft and intake manifold.

GMPP Vortec bowtie 185cc heads milled to 58cc.
Vortec Performer RPM intake manifold.

or Brodix IK 200 heads milled to 58cc.
Performer RPM intake

You will want to chop off about .040" off the heads to get to 58cc.

Install either of these heads on your block using .015" shim style head gaskets (felpro 1094) to max the cr.
(this is critical, you don't want to be short on finished compression ratio)

750cfm holley DP carb.

1-5/8" long tube headers + 2.5" dual exhaust.

Cam : Isky 280H mega cam #201281
1.6 ratio rockers.
Cam: isky Z-27 street strip solid #201027 w/1.6 rockers.




wants a 3000 ish stall 10" converter and 3.73-4.10 gears.
A 3500stall 10" converter and 4.56's is not too much.

If you want to build up this motor to use the racey intake you got,
tear it down and rebuild with new flat top pistons
get the block 0 decked.

You want a 10.5:1 finished cr.

Isky cam #201547

Brodix IK200 heads.

Wants a 4000+stall (8" -9") race converter and 4.56+ gears

The 600cfrm carb is too small for max performance.

 

Another path to 400+hp on this crate motor is to supercharge it.

Weiand 177 blower 750+cfm carb

2.10 to 2.33 pulley drive ratio

Lunati street mechanical cam 01-UF15-UF16-12
#401A3LUN lunati 73943 valve springs.
272-282 238-248-.485-.503 112lsa .020-.022 lash

Remove the crate motor heads and fully home port them
Drill and roll pin the rocker studs and install the new lunati springs
shimed to 1.70"

Limit the spark advance to about 28 deg under boost.

 

50cc/180cc replacement head

http://cgi.ebay.com/ebaymotors/CHEVR...item27babf4398