The time for the rebuild is right around the corner with most of the money saved up. Now I've changed my mind several times on whether to go 383 or just a basic rebuild/reman. For monetary purposes I've decided on the basic and found a decent shop to do it. But I also want a strong engine out of it, with the hope of at the least 350hp at the crank.

The car has never been raced by me in the year that I've owned it and will probably only see the track maybe once or twice for the fun of it. But I want to know that the power is there. I've read alot on here and read alot of folks websites on their mods and such, but what I really need is a good parts list of items that will get me to my goal. I'm no mechanic and have a hard time understanding what certain parts may or may not do for me.

Info for you folks about the car: 1989 Vert, 153,000 mile L98 TPI Auto with 2.59 gears. (thought about a gear change but so far am very happy with the highway gas milage) Only current mods are: Cut lid, 1.6 RRs, Pre cats deleted, and flowmaster cat-back.

Along with the rebuild will be buying TPiS Headers into an true dual system with X-Pipe and two Billet Cats. (with emissions) Would also like opinions on pipe size for the duals. Stock size or change?

TPI will stay with the possible addition of TPiS runners and Manifold. But would'nt mind reaching my Horsepower goal without these two items. Would like to keep the engine as stock looking as possible, aside from the headers/exhaust.

Stock 113 heads stay and will have a 3 angle valve job with all new parts but no porting. (this particular shop does not do port work)

So if any of you folks were in my shoes what would the internals of this engine be to at least come as close as possible to reaching this goal? Or is my goal unreachable within this realm?

Thanks in advance for your opinions.

 

I have a dinner appointment and do not have time to give answers to all, but will later. Go 383. You will not be disappointed.

 

Thanks Pete look forward to your response later. I really want to go 383, but the past 6 months I spent doing research the price is just not falling in line for it. The shop I found in Orlando is doing the reman for 1100.00. Price will change up or down slightly depending on what parts I have them order or what parts I supply.

Now if I could find someone local in South Florida that is willing to do a 383 for around the 2,000.00 dollar range, I'd be all over it, but so far no luck.

 

I would at least change the cam if going to 383, something like TPiS ZZ-9 or Accel 211, everything else looks fine. I would go ahead and change the intake base, runners, and port the plenum.

I would change the torque converter and leave the gearing alone, something like 2000-2400rpm would be good.

 

IMHO, when I think about getting more power it always starts with air flow. I like to think of an engine as a big air pump when I'm working on it. I'm like you I'm leaving my bottom end stock, it is an LT4 and beefy from the get go, so I'm concentrating on air flow in the heads. If I were you I'd think again about getting those heads ported and matched to your intake if you don't have the money for new ones.

Next worry about parasitic power losses, a good roller cam, roller rockers. I'm not familiar with the L98 but a full roller timing chain wouldn't hurt.

Someone with an L98 probably will chime in before I'm done posting this but cam and spring selection is critical to your combination and I'm not qualified to make a suggestion there but for a street car, something with an advertised duration of 270 is a good bet to get some rumble.

 

Why are you wanting to rebuild? Mileage doesn't mean the engine is nessiarly bad. I had a buddy that would kick my butt weekly with a 200k mile LT1 with the exact same setup as me.

It sounds like your wanting to not change much. If thats the case I would build a 350 if your dead set on building something. No reason to short change your moneys worth with a 383 with stock cam/heads/intake

 

Mild cam, you're already getting the headers, you should shop for a speed shop that does porting, for seat of the pants..I would change gears, even going with 3:07 you'll notice a difference, but you won't see a tremendous difference in MPG.

 

Perhaps, milling the heads a little, and .027'ish head gaskets. that will up your compression some. If your careful you won't need to high of octane. I would stay around 10 to 10.5:1 comp. If you could get those heads ported, that would help you as well. I'm building something similiar to yours. With all the tricks I can think of, and just running the stock cam. I looking to TRY, and get around 300hp, maybe 380 ft:lbs torque. I know I am stretching it a little, but it should be possible. You have a few more item than what I am putting into mine, and I live a an altitude of 5000ft. You might can get there. Those 2:56 gears will be a disadvantage for H.P. But good on the open road. My gearing is 3.07 dana 44. Best of luck...

 

Thanks to all for the replies so far, I do appriciate the input, but I would like to emphasize that a 383 and port work is not feasable with this rebuild.

I'm really looking to see what kind of internals I could use to make a very strong running 355, and close to 300/350 horsepower. Some of you mentioned a cam change. Well what kind of cam would be the best choice and what kind of internal parts would the heads have to have?

Alvin makes a good point, maybe the engine does'nt have to be rebuilt, and hes right. I was torn between doing a rebuild without getting the 383 like I really want or getting ad on toys and hoping that the engine will last. I chose to rebuild now and sacrifice the 383 and bolt ons to ensure myself of having a more reliable engine.

Ever since I got the car (a year ago) I've been replacing everything on it. Its like my own little daily driver restoration project. So thats basically the motivation behind going with the rebuild now.

Though I have to admit that every other day I wake up and say, "ahh, I just save for another 6 months and do the engine the way I really want". But then the flip side of me just wants to do it this way.

Anyway, gotta rush to work, I talk to ya guys later.

JB

 

Have you called Barry at Airflow Technology in Ft. Lauderdale?...he is a top drawer engine builder and sponsors the Lakeland Corvette Challenge...his stuff runs real good and stands up...I don't know his prices but he is certainly as local as you can get...

 

As a matter of fact I did go down to his shop last week and spoke with him. I did'nt get the impression that he would do a rebuild on the engine, said the guys next door to him were good though. It sounded like he only delt with port work, which he seems fairly competant of.

I got a quote around $450.00 to port the runners, plemum(sp?), and intake. Basicaly an exchange as he already had these in stock. But, suggest I just toss the heads and get different ones vs porting them.

So many different directions to go now, I'm starting to get discouraged.

 

Pete K,

Are you back from dinner yet.

 

JBI you will not need anything special for this build. I would buy a nice hyper piston, a good set of total seal rings gapless rings, bearings, and gaskets. For the cam selection I would run a hydraulic roller in a grind from a good manufacturer for the TPI engines. Then set up the heads with the proper springs and go. With the RPM you will be limited to exotic parts are not needed in the bottom end. After the engine is done, look at where you are in the budget and then start to think about intake parts which can always be changed. Heads are a good upgrade but if you are not planning on pushing for any more power you will not need them.