Forgive a newbie, but Ive got a few questions about aftermarket parts. Some things work for some, others dont. So I thought Id ask about all the snake oil remedies for making HP with an LT1. I just got a used LT, and found some issues. So Im going to start gathering parts for it, and put it in my 91 firebird, maybe next year. So, which of these magic parts dont work:


MSD Opti (expensive, and Ive read unnecessary)
58mm TB.
1.6:1 ratio rockers
Meziere electric water pump.
LT4 intake. I was actually reading here earlier, and think I have an answer.
30# injectors.
Huge cam. This is where Ill probably just call an expert. I know when Im in over my head. But Im going to be in the engine anyway. Might as well put a cam in it.
TB coolant by-pass
TB airfoil


I already have 1-5/8 headers, and a 3" exhaust. Ill also have a K&N, and a homemade CAI. Im buying a custom harness, and a preprogrammed computer from the same guy, on another site. Hes going to tune it, whenever I get everything. I also have a 4L60E, that was freshly rebuilt. The shop said he uses better than factory clutches, and bands, but it isnt a race trans.

Again, sorry if these questions are beat to death. Im trying to figure out which way to go with the parts. Itll be next year before I get it together, but Ill have a few hundred dollars till then to buy some things. I dont want to buy any useless stuff.

The car is a 1991 firebird. Im swapping the LT cause my 305 sucks. Its my DD, and I want to race it occasionally. The goal is a nice DD that runs well, and is dependable. But Id really like to run an 11 in the future.

 

Well hmm 58tb probably over kill bud i would go 52mm until you get head work also dont get huge cam unless u have your heads ported out bud and probably biggest cam you wanna go with is a cc503 or cc306 alot of people say dont go with it as dd but i am and if you get bigger cam you have to get a stall have any more ? pm ill happy to help best of my abilities

 

MSD opti -> no reason to change if yours is working, I'd go with a GM one
58mm TB -> no need to replace your stocker until you are making alot of power
1.6 rocker -> will add power, do after your other bolt-ons, ie exhaust/intake
Electric water pump -> adds about 10 hp to the wheels......make sure you know its working if the car is your daily driver...
LT4 intake -> meant for LT4 heads, not an improvement on LT1 heads
30# injectors -> only need injectors when the stockers dont flow enough, such as after a cam upgrade
huge cam -> get it if you have a 383.....not for a daily driver
TB coolant bypass -> does help, not a ton, but its free, so why not.
TB airfoil -> helps alittle, really cheap. Not needed on an aftermarket TB

 

And remember that huge cam in a DD might be an issue with passing emissions....

 

The huge cam deal is just a general "hotrod" misconception. My car is a DD, but once everyone finds out it has a roller cam, they get crazy. I found a GM LT4 hot cam kit, with 1.6 rockers, and a cam that has .525 lift @ .050. Sounds good, but might be a bit big. I dont want to have to buy a huge stall converter.

As for the Ignition. The opti on the engine is toast. Literally. Itll have to be replaced. I like the coil-over-plug kits Ive seen, with the distributerless ignition. But they are expensive. Might just buy a GM performance opti.

Im looking at going ahead and getting some forged pistons, maybe forged rods (6"?), and a cam. I guess the roller rockers ratio depends on the cam I get. But I want the roller rockers. If all this requires me to upgrade injectors, Ill do that too. I like the meziere water pump, so Ill probably get it too. And maybe a 52mm TB.
Im looking to spray the engine in the future, and think the pistons and cam are a bare minimum while the engine is apart. I can add ported heads later.

 

The GM hotcam kit is definitely not huge at all. Mild idle not even making a tune mandatory(definitely recommended though)

 

woah you are new to Lt1s.... the Hotcam is about the smallest cam out for our motors

 

a big cam (for a dd) is something like a GM847

 

For stock heads, in a daily driven car, you want something mid 220's/230 duration. Lift pretty much will only make you more power/give you a peakier motor, with no real draw backs on driveability. If I was getting an off the shelfer, I would look at the CC503. Superior to the hotcam in all ways, but has the same driveablity. Ultimately though, call me spoiled, if I am getting a cam, I pay the extra $100 to get a custom grind from someone who has built hundreds of LT1's before. Im very content with my cam from Bret Bauer, hes on here if you want to PM him, its SStrokerace I believe.

 

SStrokerace is no longer a member.

 

I think that hotcam will do what you want, no need for anything custom. Go with a proven combo thats works good.

 

The CC503 is a proven performer and totally daily drivable.

Here's an old video of my car with the 503 (man it looks slow to me now )

http://www.zmydust.com/videos/cammedoutz.wmv

 

Pull heads and have them checked out and have valve pockets ported ---this is the most restrive area in the heads (you can have the heads ported all the way if you have the money.

Install new lifters.

Install 1.6 RRs Non-Self Adjusting along with some dual springs, kit number 10308-1, from Comp. CAms. The specs of this spring should be enough for any mild cam (basically you should base your springs on the intended cam and the cam spec card will tell you which spring or spring pressures you should use with a particular cam. You will need hardened pushrods and quideplates for your non-SA rockers.

With a small cam you shouldn't need a larger TB than stock, or a larger convertor. Your rear end should be around 3.42 or 3.73 ratio.

You shouldn't need anything but the stock optispark. I would have the PCM tuned for your combination, rather than trust someone elses tune---an besides your combination may need a different tune. Mail order tune should be done when you get your stuff together.

1 3/4 headers, preferably long tubes, would be better suited for your 350 than the 1 5/8, depending on the y pipes and the rest of your exhaust, although the smaller headers will work ok.

Your stock tb won't have an airfoil and not necessary anyway, unless and until you decide to go bigger on the cam or use juice or boost.

I don't know how heavey your bird is, but if you want a mild daily driver cam that will pull stomps on a heaver vehicle like around 4000 lbs, than the Crane 227 cam is a pretty popular choice.

You stock injectors should be fine.

Bottom line is: what do you expect from your car and what type of driving will you be doing, and, of course, how much money do you have?

My guess is that you intend to keep your bird and you just want to improve your performance with around 400 hp at the crank with a combination that will not be too hard on your engine or your back card.

The above combination should get you there. There are many on this site who will provide you with better advice, I'm sure. JMHO

 

Im a bit older, so I drive very mildly most of the time. Every once in awhile, I get into it, but I rarely go WOT on the street. To many variables.
The car is basically stock weight, so around 3700lbs. And Id like to go 11s, with spray sometime. I only drive about 9 miles a day, and the track is within 30 miles. But I would like to be able to go wherever, whenever.

My budget for this year is almost gone. I got a deal on a tranny, and on a harness, so I have to get them. But before the motor goes in, next year, I have a year to buy for it. The budget is around $2k-2.5K. And whatever I can squeeze out here and there. But I want the motor in next year. Not on spray, because thats too much for now.

Heres what I was thinking:
pistons- forged
rings-total seal
cam- ?
roller rockers-1.6
Tune
rods-maybe. Thats another couple hundred bucks. But Id like to spray it big in the future (11s are gonna be fine, until I get there, then I know itll be 10s, then 9s, you know. Its a sickness). The engine is already a 4-bolt. The forged pistons and rods should be able to take a 150-200 shot. Maybe more? Ive been told anything over a 250 needs a forged crank, and a good gas. Ill cross those bridges when I get to them. But I like to plan ahead.