95camaro3800

iTrader: (11)

I'm about to start my 383 build, and I'm scoping out prices for which products/specs I'd like to go with.

First of all, here's a little info on the motor/application. It's a 383, forged internals, stock heads (will be mildly ported/polished), 16cc dished pistons, block is decked .010, heads may be decked soon as well, cam is 236/242, 1.6 roller rockers, and I plan on spraying a good amount of nitrous through it. I'm thinking about 150 shot until I upgrade the rest of my drivetrain enough to handle more. I'm shooting for ROUGHLY 400 rwhp (on motor).

Now, I need some recommendations on what parts would go well with what my goals are.
Head gaskets (brand and thickness, I'm not sure how much compression is good for nitrous applications)?
Valve springs (someone recommended COMP 26918, but I can only find them for LS1's.. any difference?)
Injector size?
Pushrod length?
Spark plugs (remember I'm running nitrous)?

Any recommendations will be very helpful, thanks in advance!

BALLSS

The 26918's are a good spring. While the heads are getting worked have the spring seats machined down to allow a 1.8" installed height. Get the Comp spring locator and retainers for the 918's. You can use your stock 7 degree locks or buy new ones.

Head gasket....IIRC Nitrous likes lower compression vs NA motors so I would suspect the thicker gasket .049 would be better.

PR's, you will need to get a PR checker for $10 and measure your set up to confirm what PR length to get. Trick Flow makes many PR's is various lengths. Many run NSA RR's and guide plates. Get hardened PR and guide plates. ISKY makes adjustables which allow you to line things up better. Due to block/head machining, higher lift cam and larger ratio RR it is typical a shorter PR is needed but you need to measure to confirm.

Ford 30 lb SVO's on the injectors

95camaro3800

iTrader: (11)

I've been hearing nitrous likes higher copression..

And what do guys run for spark plugs in nitrous-lt1's?

95camaro3800

iTrader: (11)

Anyone?

StealthFormula

iTrader: (35)

Thats what I have always heard as well. For nitrous you want to run the NGK TR6's that are one step colder from stock. Also wet or dry nitrous? If wet I think some 36lb. Injectors would be good maybe even 30's but I would feel safer with the 36's. Dont forget a larger fuel pump as well. About the pushrods like said you will need to buy the length checker and figure that out thats the only true way to know. Some more information on the cam would help for deciding what valvesprings, what brand is it? what lobes does it use? etc. etc. For reference sake I would get the PAC 1218's before I would buy the Comp 918's b/c they are the same except that Comp Cams no longer has PAC make them ,instead they have some company in Mexico make them and they have had alot of problems if you run a search you will come across some.

95camaro3800

iTrader: (11)

Ok, I wasn't sure if the TR6's worked in LT1's, I always ran them in my 3800 series II motor (previous car) when I was spraying.
And I'm not completely sure, probably wet. It'll be a while before I have the ***** to strap in the bottle, I don't feel like screwing something up, I spent way more money on this car than my previous car. I also have a Walbro 255 already in the car.

It's a Comp cam, hydraulic roller, .555/.576 with 112 lsa.

I'll look into PAC, thanks!

95camaro3800

iTrader: (11)

Anyone else have some input?

96capricemgr

iTrader: (1)

Nitrous does like compression, Roger above likes to get info from a lot of bad sources so ignore him.

I do not know why it is everyone believes 400rwhp NAis a basic number to hit and thinks they can throw whatever junk at it they feel like and get there. 400rwhp requires some well selected parts. You seem to think the displacement is important the the heads nearly an afterthought, WRONG. The heads and cam are what dictate airflow, displacement affects what rpm the power occurs at but no so much the actual power output. Meaning you need to worry about the heads more.

Block deck height should have been determined AFTER some of the things you are asking now. Guys have found stock blocks to have pistons over .030 down, you had .010 blindly knocked off chances are it is now .015-.025 put in a thin .026 gasket and your quench will still be a fairly big .041. There is some chance that the deck height is lower but not a good one.

95camaro3800

iTrader: (11)

I didn't deck the block, I bought it that way, in shortblock form.
And what exactly are you trying to tell me? Valvetrain is important in making power? I understand that, hence the reason I'm asking these questions, which is also the reason I haven't bought much of anything yet.

Also, 400 is the number I'm "hoping for". I'm expecting close to 375 or so.

96capricemgr

iTrader: (1)

HEADS and valvetrain are key, sounds like you think you can skimp on the heads.

A LOT of cars out there would have been better off if the owners had spent more on heads and less or nothing on the shortblock. A lot of weak 383s out there because people were more concerned with adding displacement than airflow.

FlamingChicken

iTrader: (2)

i would definitely drop some cash in the heads. also need to figure out how deep your pistons are actually in the hole so you can get the right thickness head gasket. i only had my block decked .015 but with the compression height on my pistons it actually puts the piston out of the hole by .001

95camaro3800

iTrader: (11)

My current motor is knocking like crazy, and was almost all antifreeze in the oil. I needed to either rebuild or find another shortblock, and found a good deal on a 383, so I took it.

Why does everyone think I'm skimping on the heads? If I were, I'd just throw crappy parts back in, and not plan on doing anything to them.. If porting and polishing is something I can do, I'll do it. If not, I can always have them done later on. I just want it running, even if it's not making the most of its potential power, for this summer. Heads will probably be a winter project, if I can't do it myself now, or find a good deal.

96capricemgr

iTrader: (1)

Mentioning the knock does explain things better. As a group we have seen too many guys add idsplacement thinking it is the key to power. You are doing a repair and taking the opportunity to upgrade what you can afford to at the moment. That is good.

"ported" means little, one places porting can ruin a set of heads and another's can make them walk all over aftermarket castings with every possibility in between. That is why we keep hammering on heads.

If the heads are 643 or 374 castings I would discourage you from porting them yourself unless you are willing to say those are the last set of heads you will put on the car. Those castings are the most desirable for serious porting and good ones are getting harder to find. Maybe try and find a different casting to play with yourself saving the desitrable ones for more serious porting when the funds are available.

I have AI heads on my sedan but the wagon is not really moddified, still though I have spare iron heads I plan to grind on a little myself just to be a gearhead and play, the car I want to be fast though I trusted professionals with the porting.

ulakovic22

iTrader: (12)

Personally I would get different pistons because a dished piston is going to kill your compression no matter what and I think you will be hard pressed to get back to stock compression ratio.

Valve Spring: Beehives are good
Pushrods: Measure
Spark Plugs: Stock or one heat range because you aren't running much compression with a dished piston.

95camaro3800

iTrader: (11)

Well, I'm taking the heads off this weekend, so I'll be able to figure that out soon, and I just found a pretty good write-up on how to P&P, so I may try a conservative attempt at it. We'll see.

Thanks again for the help guys!