Hey everyone,

Im planning on doing this swap.

Here is the list of parts i will be using to swap it in:

Edelbrock Highflow Vortec TPI Base
350 MAF ECM
22lb Injectors

What else will i need to swap this in?

Will the exhaust bolt right up?

Also wondering whether there is a difference between the truck blocks and the regular blocks.

Thanks for the help./

Sheldon

 

Should work fine. You won't have any EGR capability unless you get the kit for it.

You should use a 350 knock sensor, but the engine should have one on it if you get it complete.

The Vortec engines of that era were Gen I blocks with roller lifter cams and one-piece rear main seals. Passenger car 350's at that time were Gen II LT1 types.

 

Thanks!

I already have an LT1 cam i might put in it.

I read somewhere that the truck blocks had thicker walls?

Is this engine better then an L98 out of a 91 Z?

 

From the bottom:

The L31 is slightly better than an L98. Better heads, 4 bolt mains. Otherwise, pretty much the same.

Truck blocks are pulled from the same production line as passenger cars. They tended to have 4 bolt mains, but the castings themselves are the same. The L31 castings might be slightly better than the earlier L98 castings. But, nothing special in particular.

If you put a different cam in, you need to start doing other upgrades. The L31 cam would work well with a stock TPI setup as you described. More cam will need better valve springs, better exhaust and likely other TPI upgrades such as runners.

 

Thanks for all the help!

The cam i would be putting in is a LT1 cam at .447 lift.

The exhaust is a Heddman header system to a full 3" catback.

For the tpi, i would be putting a highflow base, runners and porting the plenumn. Then add either a 52 or 58mm throttle body.

 

I would still do valve springs. The factory truck items are pretty lame.

52mm TB should do just fine. The same 48mm that came on your TPI is used on the 500 horse 502 Ram Jet factory crate, for what that's worth.

 

Hey,

this is all great!

I was trying to find beehive springs on summit, but i couldnt find any.

Any decent springs for cheaper you could reccomend?

 

the only differences i can think of on a gen I are the main caps, freeze plugs *that's 400 only though* and rear main seal. L31 vortec heads are great to make power with but if your going to use a larger lift cam. go and have screw in rocker studs put in. the stock ones are simply pressed in and will over time come out with a bigger cam. you will have to have some clearancing done to fit valve springs IIRC. if you don't have emissions to worry about. good luck dude. i went to a 350 and i'll never look back. bigger is usually better. esp. with cubic inches. not necessarilly with cams.

 

i was so impressed with the way my wifes 99 tahoe ran i installed the same heads in my iroc. i am running a lt4 cam so i bought the sdpc upgraded heads.

 

did you have to do any mods for the lt4 cam in it ? im puting together a vortec 350 (wanting lt4 cam) and stealth ram air intake and ideas for me ? thanks