This is my first build up and I'd like to know your opinions on whether or not I'll hit my goal of 400hp(not rwhp) and I'd like to be able to break 12's. Anyway, I'm trying to achieve this with the following:

Block: 83 350 block, standard bore

Heads: a set of worked over vortec heads:
port and polished
3 angle valve job
2.02/1.6 valves
1.6 roller rockers

Cam: comp cams xe274h cam
lift(with roller rockers):519/523
duration:230/236
LSA:110

Intake: lt4 intake converted Lt1 style, gasket matched of course

I have all of the parts except for the intake which I'm going to be getting this week so this will be the final engine whether I make my goals or not. I was just curious as to what ya'll think I'll achieve. By the way, especially what do ya'll think of the cam? Too small or just right? My brother keeps messing with me that its too small but he's the type that would like to make all kind of nascar sounds before going anywhere.... so yeah I need reassurance that I made the right choice He keeps telling me lt4 cam but maybe its just me but I don't really see much of a difference at all between the lt4 and xe274. Ok, I'm babbling now so I'll stop but please do tell me what you think.

 

Quite posible. The quality of your exhaust system will play a big roll along with the assembly of your engine. I'am a fan of smaller cams with high lift and everything else being optimized. So for me building a car mostly for the street with an occaisonal run at the strip I would go no bigger than say the LT1 hot cam(1.6RR) or something in that duration range. Now if your car will be mostly for the strip than a larger cam would be in order. Looks like you have already bought your cam. Good luck with your build up. Allen

 

yeah the Lt4 hotcam with the 1.6rr should work fine. Also the comp xtreme energy 224/230 cam would work good. your cam seemsquite big for 350 but would work good with good tune and lt1 intake.

 

Thank you for the answers. For a track time I know you'll need to know additional information. I haven't quite ironed it out yet but I'll be running around a 2400 stall, 3:73's gears, and I already have longtube headers into a 3 inch catback exhaust from a '99 ss . The car is for the street so I can't really run a bigger cam.

 

That combo seems good enough that it will make atleast 400 hp. that should get you mid 12's for sure.

 

LT4 intake converted to LT1 ?

The LT1 doesnt fit on vortec heads, hence the high ports of the heads ..

How did you fix up the LT4 ?

 

It's not an lt1 intake, its an lt4 intake converted just like the lt1 intake is. The taller ports of the lt4 intake are very close to the raised vortec intake ports. It's supposedly only a gasket match port away. Someone has done the conversion with the fastburns, which have the same raised ports as the vortecs so there is no reason it shouldnt work. I'm going to be getting an lt4 intake gasket this week to see how it matches my vortecs. This has been up for debate for a while, I think I've read every single post on this board about it. I'll take pics of the gasket to head match and post them here when I get it and if everything looks good I'll go ahead and go through with the intake conversion right after.

 

is there any reason you want to go with vortech heads?

 

I'd say because he already has the Vortec heads.

 

Interesting, nice to hear there's an other possible option for the vortecs !

 

Took the words right out of my mouth.

 

One of the critical areas is compression ratio. What will yours be?

Remember, each point in compression is worth about 4% is power.

I remember one of the mags ran a series of tests on a 350 using Vortec heads and a CompCams camshaft (224/230 on 110s), 1.6 RRs, but it was a carbed engine running a 750 with 9.4 CR.

It made 402 Hp at 5800 and 416 in TQ at 3600. 1-3/4" headers and Borla XR mufflers added 6 HP and 13 in TQ.

How those numbers would compare to a FI engine is anyone's guess. Generally you would gain torque but lose top end HP with a FI setup Vs a carbed engine.

I also believe that the 230/236 cam is too big for a stock bore 350. You'll lose a lot of low end torque.

You should be close though.

Jake