Howdy all!

I just wanted to run this combo by you all to see what you guys thought. Most of my truck buddies run carb, and don't know nearly as much about EFI as some of the guys on this board does.

Right now I have a TPI slapped on top of a stock rotating assembly / heads, with a cam that has too high of a powerband for the TPI intake.

So, I want to built a new engine with EFI in mind. I've got a 1 ton 4x4 truck that is used for daily driving, with regular towing jobs, and the occasional spanking of some riced out import off a red light, LOL

The truck has a 5 speed standard transmission (NV4500, compound low first gear, three normal gears, then a 5th .73:1 overdrive), with a NP205 transfercase. The gears are 4.10s, with 33" radial tires.

My primary goal is torque -- Horsepower comes second.

Now, I've got a fresh 350 4 bolt main block, with a .030 overbore ready to build, so here is the engine combo I am planning on:

Aluminum L98 Corvette Heads with mild home port / polish job
Pistons to bring the compression ratio to approx 9.6 - 9.8:1 (I want to run 87 octane, hense the Aluminum heads)
Cam with specs similar to 212 in. / 218 exh. Duration @ .050, .449 in. / .456 lift, and an LSA of 112 degrees for a very smooth idle, with very strong torque. Should be good from idle through 5200 RPM
LT1 intake modified for use on a small block so I can use all 5200 RPM. My current TPI intake falls flat on it's face at 4700 RPM.

What does everyone think? Any adjustments that you'd make? I am fairly set on using the Vette heads, as this engine has to be built on as little money as is possible, without compromising quality. I feel the Aluminum L98 heads with a mild home port / polish job should flow plenty well to 5200 RPM when the cam starts to let off.

Thanks!

Russ

 

Since you're planning on running this in a truck and want that low end torque I'd stick with that TPI and do some porting to it (if you don't want to invest in a different manifold and runners). A LTR setup will give you the very strong torque you're after while letting you spin to about 5k on a ported job.
The LT1 intake was suited for the LT1, like the LS1 it favors higher RPM's while sacraficing low end torque. The rest sounds great!

 

More lift on the cam.. may have to work on the heads a bit to accept it, but LTR TPI's like the short duration, high lift profiles, built on 112 or so.

 

lt1's make more torque @ a lower rpm than tpi's. Tpi's make more torque @ 3500 rpm's then die out like an old smogger shortly there after. If I were you, I would spend the extra $100 or so and build a 383 as opposed to a 350, use vortec heads if you don't already have the l98's, use a comp xe262 cam and run a vortec stealth ram.
I say use the vortecs for two reasons: 1. they have efficient combustion chambers and will allow you to run 87 octane with 9-9.5:1 compression and 2. they are cheap and will make more power than l98's.
I say use the stealthram because I have been scared off the lt1 conversions after hearing about potential sealing problems resulting in coolant in the oil.

 

check fullsizechevy.com, it's a truck board. My brother is a member there, its a really big forum, and I think there's a lot of knowledgeable people there. (might know more truck specific info too)

 

I've never heard of LT1s making more low end torque than LTR setups...

If you are looking for a lot of low end TQ DO NOT go Stealthram. I have one and compared to the TPI setup you loose a ton of the TQ we all love...

 

I won't use Vortec heads becuase of the requirement of a vortec specific intake, and their thin, easily cracked casting. For a play toy, they'd probally be good, but for a work truck, I'd rather something that can take a bit of heat before cracking on me!

I would be willing to sacarfice a bit of torque just to have that extra umph up tops, but I think I'm going to see how the TPI intake performs before I go ahead an buy an LT1 intake and have it machined. For all I know, it may perform plenty well enough for my liking!

This truck isn't built for racing, so I am not sure how often I'll be revving up past 4500 rpm anyways.