Hey guys, might be a long one but I’ve been looking for help and I don’t get any email responses back from shops, nor do I really know anyone with an LT1, but here goes…
I currently own a ‘94 Z with the 350 LT1 Auto that has 113k miles, car has cracked heads unfortunately so I’m looking to build it now, I’m looking to make a fun street car, that can surprise people but nothing where I’ll be uncomfortable the whole time, but I do have higher tolerance I’d say, I am young (22) and still have a good back aha. But anyways, suspension work is done to the car already, looking at Monsters 600hp capable tranny and that is set there. Other current mods I have are,

Longtube Headers w Magnaflow Exhaust, SLP Cold Air Intake, Edelbrock Intake Manifold, Holly 52mm Throttle Body, Upgraded Fuel Pump, 160 Degree Thermostat, and I’m looking to get 32LB injectors from Racetronix. It has a STOCK Bottom End

So now to the meat of the post, I have a couple mods picked out that I would like to add to the car, these being AFR 210cc Heads, Tick Master Stage 3 HMB Cam, 3600 or 3800 Stall TQ from FTI, and an MSD Opti. I need guidance on what I should I do while the engine is out and pricing, I’ve read multiple things from just rebuilding the bottom end, getting forged pistons/rods, resealing gaskets, but I’m not sure exactly what each entails and what parts to buy, or what exactly to do, I just have the main parts picked out but what little miscellaneous bits will I need, expect to replace, stuff like that? In the future I plan on adding nitrous (100 Shot Max) but that’s all I have planned really. What’s a good price estimate for what I want done+labor? I honestly have set aside, I’d say $7000 for parts, and a couple more for labor as I can’t do anything myself, will I need to keep saving or is it doable? Thanks for any assistance

 

Just to be clear, you are looking to achieve 450 rear wheel HP through an auto (4L60E ??) trans? And is that before or after adding the 100-shot of nitrous? Wet or dry nitrous?

Just curious - what “cracked” the heads? Did it cause any other damage to the block or rotating assembly?

Couple things that stand out to me as not a good idea:

- Edelbrock LT1 intake. Tests (many years ago) have shown that raising the floor of the plenum to create the “air gap” reduced the plenum volume, make it unsuitable for big HP.

- MSD Opti. After what - 20+ years ? - they still encounter problems. Might get one from a good batch, might get a dog. Best unit available today is the Petris. But, just recommended that unit, and they told me it’s out of stock until 7/2023. Seems everybody today wants to drop big $$$ to pick up the Torqhead or EFI Connection 24X conversion. Runs on an LS1 PCM with 8 coil-near-plug ignition system.

- the best LT1 heads are produced by Lloyd Elliott, or Advanced Induction. They can do amazing thing with the right stock LT1 castings, but unfortunately yours are “cracked”??. But, you can still find stock LT1 heads fairly cheaply. LE and AI also offers TrickFlows, and can rework factory LT4 heads. And both can offer a cam carefully matched to the head flow capabilities and you personal use requirements.

- 4L60E rebuild - consider Cahall (CPT).

Answer the questions in the first paragraph regarding rwHP and the rotating assembly can be addressed. Injectors may be marginal.

 

Yes I am trying to get as close to 450whp before adding a wet shot of nitrous, it was taken to I believe 3 mechanics where they mentioned thermal stress though my dad was the one driving it at the time, overheating I’m assuming but I’m thinking he drove it some distance causing more damage, but the rest of the block/rotating is fine, supposedly, I never got to get a deep dive and the car hasn’t moved in ~2 years, I’m just getting around to it now honestly.

I didn’t know that about the Edelbrock Intake, do you have a good recommendation for one I could use for the power im looking for?

Also, again, didn’t know that about the MSD, made a post on FB and all I saw was they make one of the best Opti’s for the car, I did see Petris recommended but also did hear they’re hard to come by, and I did get told I should just look into the conversion to another system like the Torqhead or even Holley EFI? I think but I don’t think it’d fit in my budget

Ive tried emailing LE cause I saw they’re LE2 package and the numbers are there but I haven’t gotten a response once unfortunately so i don’t know if I’m putting the right info in or just not making sense to them, and for AI, first look throughs, I see their 200cc Comp heads, I’d reckon they’re a good choice no? Seem like the most popular

thank you for the 4L60e rebuild suggestion, will look into that

 

If you want to go with the Facebook info, that’s up to you.

 

well that’s why I’m here as well, i mean I’m trying to get different views on what is the best route and recommendations to take to achieve my goal, and do my own research as well which I clearly need to do more of, thank you for the help so far tho

 

I’m happy to see the interest in 4th Gen fbody’s is starting to grow. We may start to see an increase in web traffic here.

First, a couple of things. Welcome to this site. It is a gold mine of information that has been shared by some of the best with these cars. A quick search and you will find what you need. Consider this site the Bible of 4th Gen’s. Also, Injuneer is the GOAT when it comes to these cars. We are lucky that he is still around on this site.

For a fun street car you don’t need to do much with these to get it there. For starters, the power is there. GM engineers made sure to hide as much of it they could so it wouldn’t **** off the corvette owners. However, looking at your mods list, it looks like you want to create power for a strip or track car. If that’s the case then you will be spending a lot more to upgrade tranny and rear end as well as the right suspension mods to be competitive. However, if your true intent is the have some fun red light to red light and donuts (these cars were made for this), then don’t focus on numbers but, instead look at improving what you already have. For example:

1. Stock intake: Polish and Port is all you will ever need to do. Have it done the same time you have the heads done. He will even port match it to the 52mm TB. It’s already close to that now so it won’t take much.
2. Stock heads: same as above. Have the heads rebuilt and p&p. I highly recommend Lloyd Elliott for this. Tell him what your goal is and he will recommend the right cam and build for the heads that will support each other as well as the proper stall speed for your torque converter. Since yours are bad you can find others in the salvage yards. They are scarce but they are there. If not, get the AFR’s from him.
3. Torque converter: Once you change the cam you need to change the stall of the TC. Lloyd is an expert on this. He will be able to tell you exactly what you need.
4. Stock bottom: Since this is a stock bottom, there will be a limit on how much hp you can safely make. However, you will still want to refresh the bottom end with new bearings and ARP bolts to keep it together, especially if the heads did crack. 450 crank is doable but you will start losing reliability past this point.
5. Optispark: MSD is a well known brand. Unfortunately, buying an optispark from any manufacturer is like playing the lottery. If it isn’t a GM made one with the Mitsubishi optical sensor, you really should be looking at Petris. However, the pin drive one is hard to get. I have one from Summit Racing and I have been lucky with it. However, the water pump still sits on top of it and when it decides to take a leak, it’s pissing all over it. For reliability and for tuning go with Torq Head or EFI Connections. Is it expensive? Yes, more than the car is worth from a resale perspective. Is it reliable? There are tons (literally) of cars out there running LS ignition without any issues. There are hundreds of optispark cars still on the road and maybe 80% have or are having issues. Optisparks are the leading cause of putting a lot of these cars in the junk yard because people are tired of trying to fix them.

My point is this. Make sure that you know what you want to do with the car. Then before you start throwing parts at it to make it go faster, get a set of factory heads and send them with the intake to Lloyd. Buy one of his custom grind cams and change your TC and you are close to your 450HP already. These cars can be a lot of fun using most of what came with the factory. With some massaging and focusing on specific upgrades, you can feel a big difference. Enough so that you will quickly realize your next upgrade will be the brakes!

 

Problem is he wants 450 HP at the wheels. Using the traditional 15% drivetrain loss (which is optimistic with an automatic) he's looking for at least 530 HP at the flywheel. Run down rotating assembly might not be happy.

Other problem is he says his heads are “cracked”, but it’s unclear what that entails, or whether there is other engine damage.

Doesn't appear to be anything in his budget for suspension or drivetrain.

 

I've owned my TA for 20+ years and I can tell you the above advice is very good advice. You are doing the right thing in doing your research before beginning your project. At the risk of sounding redundant, your heads/cam combo is critical so it makes more sense to go with the above mentioned people who can tell you what you need to meet your goals. Don't skimp on internals especially if adding a power adder is in the future. If I were starting all over, I would probably bite the bullet and convert to the Torqhead or EFI Connection upgrade for reliability and tunability, although I have had good success with the Petris opti. Good luck with your project. Take your time and you will have a lot of fun.

 

OP

You are getting VERY good advice. Abandon everything on your list

Lloyd is very easy to get ahold of and can do a head and cam package to meet your goal of 450 RWHP. With that said your current bottom end will nowhere in any way tolerate that. You would be in the solid lifter, fully forged, 4 bolt rotating assembly realm. You just blew by about $8-$10 k in a blink on a motor set up to do that more than once without even upgrading you trans, rear end, suspension

Stay off FB for any valid advice. Re-group your thoughts. Having a 400ish RWHP F body is very doable and with a set up that is fun and comfortable to drive. A 130k motor that cracked it's heads needs a rebuild to deal with the kind of power you want at any level

 

“ReyeZ28” hasn’t signed back in since 11/23. Guess my Facebook comment offended him.

 

Hiiii, I’ve actually learned a lot more since I’ve last been here, honestly just couldn’t remember my password lol, but if anything I’d like to thank you and everyone else here for the info. Though I’m in a pickle rn and just maybe you have info on anyone but uhhhh, I ordered the 4L60 trans from Cahall like you mentioned, March 2023, and fast forward to March 2024 Gail gave me a couple final updates saying it was almost ready but then idk if you move heard but she has passed at the end of March so I’m kinda in limbo right now, sooo if you know anyone at all I can get in contact with there, I’d very much appreciate it :,(

 

I was aware of her passing. Cahall was a sponsor on ltxtech.com. The news of her passing was posted there. I added a post too the thread asking for contact info for the business.

Like this site, traffic is way down, but I'm hoping the active member who posted the news will respond.