Ok, I've been thinking a lot about this lately and I've decided to spend my tax return on a stroker kit, but I'm not sure what to upgrade and if I'm even going to be upgrading what I should. First off, I own a 93 Z28 M6. She's got 69k on her, so I'm not too scared about what I'll find when she's torn down. The tranny is the upgraded M29, I know it's still not as great as the 94+ T-56s, but it's a start. I have the sport suspension package that was offered in 93 with the "sport" gear ratio of 3.23. Everything on the car is stock, except for the headers. I have two choices for a stroker kit. A 4340 Forged 383ci Kit or a 4340 Forged 391ci "Monster Mouse" kit. I'm leaning more towards the 383 because it's almost $2k less and I can use that money to upgrade my car. Now here's a list of things I feel I need to upgrade;

Motor
- 383 or 391 Stroker Kit
- Stock LT1 Heads, Ported and Polished (Upgraded componants listed below)
- ATI Damper
- Elec. Water Pump

Fuel System
- 30# or 36# Injectors. 30 would be fine for what I'm doing, but 36 would be better if I'm planning on more stuff in the future. Anyone?
- Adj. Fuel Pressure Reg.
- Upgraded High Flow Fuel Pump (or should the stock unit flow enough?)
- 94+ Intake and Fuel lines

Intake
- 52mm Throttle Body
- Airfoil (Screw it, can't hurt. The kitchen sink is goin in anyways, )

Exhaust
- Long Tube headers
- 3" Exhaust System (Cat is gutted, no worries there.....)

Drive Train
- 1pc. Alum. Driveshaft
- New Posi Unit (Rumor has it, the 96 - 97 cars had a stronger unit. True? Can I get one from those model years and swap? Or can I still use mine?)
- T/A Rear Girdle
- Moser Axle Spindles
- 3.73 Gears (Heard that with the M29, 4.10 Gears would be a waste and the 3.73's would be better. True??)

Valve Train
- CC306 Cam (Already have LT4 springs, locks, shims, etc.)
- 1.6 RRs
- Do I need new pushrods? I heard that 93 LT1s came with hardened pushrods and they should still be good for the new motor setup.... True?
- LT4 Heavy Duty Timing Chain

Electrical System
- 95+ Opti and wiring (Have new Opti, some wiring)
- MSD Ignition and MSD Coil.
- Computer Chip Reprogramed

Transmission
- LT4 Upgraded parts? What can I do to make my M29 Withstand the new massive amounts of Torque??

Brakes / Suspension
- No kit picked out yet, more than likely all new suspension componants and powerslot rotors.

Anyone have any suggestions? Anything I'm missing? Any advice is much appreciated!

 

Alright I will try to answer a few of your questions and try to help you with some advice on some of your upgrade components.

First off, if the Monster Mouse kit (which I have never heard of) really is 2000K more, then just get the 383 kit. The rotating assemblies are on sale right now at Combination Motorsports for a very good price. The 383 will make a killer starting point for any type of direction you want to go in the future, be it forced indution, Nitrous, etc...

As far as components:
I would just go with 30# injectors. That is all you are going to need for that setup. I would just wait on the 36#ers until you need them. An injector swap is very easy on our cars.

Electric water pump is a good idea.

If you go with a cc306, it will literally CRUSH those puny little LT4 valve springs. Those are rated to like .525 or something and the cc306 with 1.6 rockers are damn near .600 lift.

New pushrods wouldn't hurt. You can always check your stock ones for any bent ones. But with spending that much on a motor, doe sthe additional 35.00 for a hardened set really make that much of a difference?

Feel free to email/PM me if you have any other questions. I am just up in Dallas and can help you out if need be. I amin the process right now of putting together a LT4 solid roller 383 with a 300 direct port shot that shoud be making just under 800rwhp. So I can give you pointers on deals/info that I get along the ride to stroker-ville

Matt

 

Thanks for the advice! I've been leaning towards the 383 for some time now anyways, just because of the price and so I can do some much needed upgrading to the ride. I'll def. hit you up if I run in to anything I'm not sure about.

 

why would you want to use the 94+ intake?

 

You wont need an intake foil if you go with an aftermarket throttle body. If you are gonna buy aftermarked i would go with a 58mm just because its only a few bucks more. Also Monoblades are about $500, but if you arent S/C it, you dont need one.

For your heads i would get them ported by Lloyd Elliott, he can get themto flow about 275 on the intake side with his LE3,and custom grind you a cam for his LE3 which is bigger than the CC306 and GM847. It will act like an 847 would in a 350, in a stroker.

You should get Hi-tech pushrods. they are about $100 a set. Pushrods take all of the beating from your camshaft and flex. The more they flex, the more power you lose. I wouldnt skimp on that part.

you can use your stock lifters with only 69k on them. you will need NSA 1.6RR's if you got with Lloyds heads. self aligning won't clear his springs.

I would go with the Summit X-pipe kit. It is about $100 uncludes the X pipe, the pipes to the headers, and the pipes to the axels. you put on the mufflers and tips you want.

I wouldnt spend the extra for an LT4 timing chain. you can get a Cloyes double roller kit for $79 since you have an electric water pump. you will have to grind out a little of the timing chain cover.

30# injectors will be fine. Upgrade the pump though. My friend dynoed 378rwhp on his stroker and fuel pressure fell off around 6,000 rpms to 24 psi. He had the stock pump. If you need bigger injectors you can always upgrade them with ease.

i would also get a dyno tune. They can get a few more hp out of it, but also increased mpg. I would get one just so i know my engine is running perfectly and so i know nothing will break from a miscalculation or personal error on the parts description.

 

Your gunna need a 12bolt if you plan on putting down any serious power.

 

That's not true. you could get about 6 10 bolts for the price of a 12 bolt. You will break your rear end eventually though, especially with a manual and sticky tires.

 

While that may be true, what is your time worth to replace 6 rear-ends? Save your pennies and do it right...once.

 

I agree on the 383 route. For me, the little additional displacement is not worth the expense of the kit (I'm assuming you're referencing the Speed-o-motive kit).

Let the guy designing the valve train decide what components you'll need to reinforce or compliment the valve train. Yes, you'll need different push rods - the length of which you will not know until you mock-up the engine. As mentioned earlier, the LT4 springs are completely inadequate with a CC306. Again, let the guy designing the valve train do all of it, including cam selection - pay for this expertise if you are otherwise guessing. I have to chuckle at some of these posts where the cam is chosen before everything else is determined- it should be one of the last things chosen IMO. Talk with LE and AI about set-ups and budgets that suit your needs and goals.

As far as injectors are concerned, the 36# will likely suffice for now, but if your plans are bigger for the future, it will do no harm to step up now to a set of 42#, as long as the fuel trim is adjusted accordingly - but this applies to any injector bigger than stock. Injectors aren't necessarily cheap, so buy what will serve your needs the first time around.

The rest of your parts look reasonable (52mm TB usually come with built-in air foils), but you didn't list any suspension parts, so we can't really offer any feedback.

 

if you want a bit bigger combination motorports has a 396 kit that is about $50 more than the 383 kit and both are forged. I'm getting a 396 kit for $1497 plus some extra to have it balanced.

 

When you get the heads done,replace all the valves with longer stems and you can run whatever lift you want and have a much bigger selection of springs.
Go with a 383 the chances of hitting water when grinding the block is much less.

 

Thanks everyone for the advice! Since this buildup is going to take me a lot of time, I am going to buy a 4 bolt main LT1 block from a vette and start building on that. With a new baby daughter it's gonna take me a while to save up, lol. That way I can at least keep the Z running till I have everything ready to swap in. I've printed off this page and am going to keep it to help me in my search for parts, thanks again!

 

i don't think i would get and lt-4 block with a 4 bolt main.....i would go with splayed mains. It is stronger and you can keep the original block.

 

For the block any 2 bolt block will suffice you can add 4 bolt maincaps to it at the machineshop.

What power levelare you looking for? if your not wanting over 450 rwhp N/A then you can really save some money by using a cast steel crankshaft.
If this is your range I would do this..

Eagle cast steel crank 1 peice rear main seal (in Jegs right now for 192$ plus shipping.
Some nice rods, pocketbook ,your choice I would use either Eagle I beams or the Hs they are priced right.

And some JE/SRP forged pistons, pay attention to the dish or dome you dont want rediculous compression, 11 to 1 will suffice.

LLoyd will do the heads up good for ya as can others, you'll need that cfm all across the board not just at peak lift, so compare their advertized #s not just at peak.
A cam in a 350 will behave much tamer in a 383 so er on the big side to that effect but a cam in the 240 duration .050 range and close to .600 lift with 112 to 108 lobe sep. The head porter can usually give you good idea of what works with his heads. Let the head porter select and set up your springs, let him as well advise you with the rest of the valvetrain.

While I would budget 2500$ for the shortblock (including machining and assembly) I would budget about the same for the valvetrain and heads.

Add a computer tune (and later a dyno tune), fuel pump, injectors (36s are best but if you stay below 6500 and 11 to one compression 30s will work) and valve body then all you need to do to complement the motor is the exhaust.
383s like to breath deep!!!

If you have the cash after all this I would definately upgrade the rear.

 

For the power levels we're talking about here, the straight 4-bolt will easily suffice. Personally, I don't believe the splayed 4-bolt is any better anyway - they both have advantages and disadvantages.