Hi everyone-
First off, I'm a new member and am thrilled with all the info I have found on this site!

Now for my question...I have a 1994 Z28 with the LT1. Its in good shape overall, but the motor is tired with approx 100,000 miles on it. No oil burning or problems, but its tired.
I have been toying with the idea of taking the car and really hopping it up, from ground effects, to wheels, to a new interior, paint, all that good stuff. Since I build and paint custom Rods and Harleys, the paint and stuff is not a problem. The motor is.
I was just going to rebuild the motor to stock at first, but have stumbled on a couple places that are selling 383 LT1's pushing over 400 hp on pump gas. That has my real interest now, since I'm going to all the trouble with everything else- I want a screamer.

Bottom line is this- these 383's are running in the neighborhood of 6 grand. Would I be dollars ahead going with one of these "as built" motors, or going ahead and tearing down my current motor, have a machine shop bore, hone, deck the block and assemble the lower end, and then just bolt on AFRs and finish the motor myself?

If I do go it on my own, where do I find the crank, pistons, etc needed to build the motor? I also have read that there are some problems in the bottom end when using a 5.75" stroke- the factory block has to be clearanced.

I'm no slouch when it comes to motors- I have built my last 4 H-D motors (all 4 pushed over 140 HP to the rear wheels) and I also assembled my 302 out of my 69 Z28. However, these Gen II motors are a little different creature from what I've been told.

Any help or advice is certainly appreciated.

 

first you dont need a 383 to make 400 hp on pump gas you can build your 350 easily to 400+ hp with a cam, porting, injectors, headers, and intake bolt ons. If your looking for more like 450 hp you can step up to a 383.

the 383 dosent have a 5.75 stroke its a 3.75 (typo?) buy yes some clarencing must be done check out his page it has a pic of what has to be clarenced, http://www.grapeaperacing.com/GrapeA...maro/block.cfm

for all the parts look order a free summit catalog they have all the parts you will need to build a stroker i belive they also have a stroker kit with all the parts you will need with the 1 piece rear seal crank. I know Cat makes the cranks for the lt1. http://www.summitracing.com/store_bin/freecatalog/

about the cost you will spend about 3k-4k on a 383 build.

 

Thanks for the reply Turb0-
Sorry about the typo, I must have been thinking about the rod length.
I looked up a 383 at Golen Engines and you are right, they are running in the 480 hp range on their strokers.

I will check out Summit Racing. Any suggestions on piston type?

 

Callies or Oliver rods would be my choice, and JE Pistons (Ultra-lite version) are a very good combo. If you go close to 500 rrhp, I would get the 2-bolt splayed and the rotating ***'y balanced as a unit (.5 to 1.0 gm.) for high-revving applications. The power is really in the heads. Obviously you need fuel and flow, and a good choice of cam. I would call someone like Cam Motions to suggest a cam for your combo. A 355 c.i. would be perfect for a 400 hp engine. If you want to stroke (383) cheaply, any Chevy 400 c.i. forged crank (3.750) would be acceptable. If you go 396, you will have to get an aftermarket custom crank (3.875), as chevy (to my knowledge) didn't have a production 3.875 crank....
I really don't know if the 396 is worth the extra $$$$$....

 

Since you are going to building up an LT1, and there are numerous people who have done this on the "LT1 Tech" forum, that would be a better place to start. I believe there is a "stroker guide" that has been published by "Jim S." and would help you with the intitial plans on what to build and which way to go. Maybe someone can post the link for you.

There is a broad spectrum of options, and 450-550flywheelHP out of a 383 isn't a stretch. Cost can range from a few thousand $ to $20K with a major power adder in the 750-1,000HP range. It's all been done, and the people who have done it frequent the "LT1 Tech" forum. Most of the people with LT1's that post here on "Advanced Tech" also post there.

Moving to "LT1 Tech"......

 

Ive got about $2400 in machine work and lower end parts....SRP forged pistons, eagle h-beam rods, and eagle forged crank. That includes balancing the rotating assembly and installing 4bolt caps.

Im only going for 400hp NA because Im going to run a fairly small cam for emission reasons and stock ported heads. I do plan on a 150 shot of nitrous so I went with all forged on the bottom.

 

off subject, gb95zconv what you put into the botom end should handle alot more than a 150 shot more like 250