GMPP Crate engines.

[Crow66]

Hey Gearheads, I'm swapping my '72 Monte 355 into my old Vette, and replacing it with a new GM crate motor. I like the FastBurn385 #12499710, and the HT 383, #12499101. Both are fairly different from each other, as the stroker has the Vortech heads for a lot of low rpm torque around 400ft/lbs at 2500, but low Hp,(325) as compared to the FastBurn headed 350 with upto
430 Hp @ about 6000 rpm with the HOT cam and 1.6 rollers.
I'm asking if anyone has had any experiences with either of these motors, good or bad.
My Monte prolly weighs about 3800 lbs has TH350, and 3:73's. I'm leaning towards the HT 383, but don't know if my car can handle all that torque stock, upto 450 ft/lbs. I'm only using it as a summer cruiser, not a dedicated racer. Anyone tried these crates before?
What kinda suspension, cooling, tranny upgrades am I looking at with either of these motors?

TIA

[MrPbody]

It has been our experience, "craters" are okay, but not all they're cracked up to be. In general, the first thing we do to a "performance" small block is take it apart and "blue print" it. Production engines from Chevy are kinda "sloppy" when it comes to machine work.
A good machine shop can build a much more powerful and efficient engine for about the same money. You just have to wait a bit...

As for the choice, the E-body (Monte) is quite heavy, as you've stated. The high torque engine would make the car a much better performer at street speeds.

Jim

[Crow66]

That pretty well answered those questions Jim, thanks.
If I decide to go with a builder, of which we have 2 excellent shops (1 of them rebuilt the Monte 350 thats going into my 'Vette, his brother is a 3X I.H.R.A. champ.) here to choose from, do you think the basis of the terrific torque from the GM HT 383, comes from the vortech heads? Do you know of an aftermarket head that could replicate these great torque levels but improve on the HP curve?
Or would a different cam with the stock heads be the answer?
I'm also looking at rebuilding the TH350, can I make it strong enuff for this kinda torque, or should I get a 400?
Thx again.

BTW, It's an 'A' body 1972 Monte Carlo.

Sherman.

[MrPbody]

Sherman,

The Vortec head is a good one. They're readily available and rather "cheap". There aren't many better choices for a "stocker". Maybe World Products S/R or S/R "Torquer". I would use a 4-bolt 350 block, stroked to 383. If you intend to keep the revs under 5,500, the "cast steel" aftermarket cranks are up to it, and VERY cheap (about $200). If you want more, you should use a Chevrolet casting (400 small block) machined to fit the 350 mains. If even more power is desired, use an aftermarlet FORGED steel crank. Not cheap...

If you want the most power in the range, use a Comp XE262H cam. Tons of low-end and reasonable high-end. Performer RPM Air Gap is the intake of choice.

Lots of good parts for the 383 out there!

Jim

[Crow66]

Okay, I've narrowed it down to the HT383 longblock, what kind of machining do these blocks need outta the box? I'm gonna use the RPM Air-Gap, 1 5/8 headers, and 750 cfm.
What polish/port/balance/blueprint work is necessary, if any?
T.I.A.

Crow.

[Crow66]

achoo!