I know this has been asked before, and I have even asked a version of this before. But now that I am well into the restore, and the wife has made some choices for me (since it is her car eventually) I thought I would ask again.

I had all along planned on going from the stock engine to a 383 to get to about 425HP, and swap the hood to facilitate it.

Notice the "had".

The wife wants to leave the stock hood so that will affect any decisions on getting more HP.

I do plan on putting on side pipes, keeping my TH400 and the rear gears have been re-built using the same gearing.

What types of changes (and which parts) could I make to exisiting engine to bring it up to a more fun level (350hp ish). I figured I would go with aluminum heads, and manifold but not sure which of each.

Again, still not sure the path to go just trying forumlate ideas and get some direction.

Thanks in advance
Eddie

 

Aluminum heads
Roller cam
L82 intake

Might not be 350hp, but will be a lot more fun to drive.

 

Budget is the first question here - everything else flows from that

What is the current gearing?

 

I am in the process of budgeting actually, but am probably doing it backwards am looking at options then deciding on the money part

3.08 I think is the gearing.

 

When there's no buget...the options are virtually unlimited and it's pretty darn tough to make any kind of recommendation :/

 

Why do you have to have a hi-rise intake to build a 383? I had a street racer buddy years ago running around with an 11sec Nova with a 410cu/in motor topped off with a cast iron Qjet intake. We made lots of $$$ with that car back in the good old days.
Build the 383 and make it look stock.

 

I'm curious why wifey thinks she needs 350ish horsepower? She certainly downgraded her needs from the original 383 cubes and 425ish horsepower. Women, huh? They don't know what they want. Or perhaps hubby is just playing a fantasy game out loud?

 

Speed costs money.
How fast do you want to go?
Really, without spending too much, look at a free flowing exhaust (2 1/2" pipes), high flow mufflers, a K&N type high flowing air cleaner, and a recurved distributor. That'll wake that puppy up. To help the reliability, put in an oversized engine oil filter, from a pickup or medium duty truck.
Those are all "bolt ons". And relatively cheap. But if you decide to open up the engine, I promise, you will start spending money in a hurry.

 

I was told that to get the horsepower, I needed more clearance and the L88 4" would be the better choice for that.

She doesnt really care about the HP. But she did have a nice 96 which she loved the ummph behind it. The 425 was really for me (I come to realize), but once I realized it, I decided to go ahead and down size it some from what I would want, but still give her something fun to get into ( because she does that from time to time). The 350 seems like a fun HP rating and not be going overboard.

I figure a couple grand ( 2000-2500ish probably not counting the header cost & side pipes since I figured than in seperately). My real thing is I had already figured a fully newly built 383 would have been much higher than just altering the original engine.

basically as fun of car powerwise that is still street nice, that will maintain the look of the car (Which is her only reatriction so far)

 

The budget helps a bunch. For a couple of grand, I'd probably look at a Vortec top-end swap along with a cam and Edelbrock Performer (not RPM). That's a major improvement in power with a relatively small investment and a fairly easy upgrade. Aluminum heads really aren't required at this power level.

Scoggens-Dickey makes a nice Vortec top kit, and there are others.

http://sdparts.com/details/scoggin-d...nter/sd8060kit

The devil is in the details, so if you're looking at this route we need to talk through the specifics. There are a lot of other small touches here that will add up a bit

 

I had sent a vendor a request, and they also suggested a top-end swap. I have a feeling that is the route I wanna go. kits are easy but not being an engine guy I dont know what should be added with it or even if the kits are configured to play optimally together.

 

Many kits are vendor-specific, and it's easily possible to get either a mis-matched combo or pay too much. The SD top are GM and Edelbrock parts, very well matched - combine that with the right cam and you've got a pretty much ideal configuration.

 

1: make it real loud and she will think its got 425hp!
Aluminum heads are not required for any power increase.
The only advantage they have over iron heads is weight.
Another thing with aluminum heads is sometimes you have to figure out if you need longer or shorter pushrods because they way the increase compression is to shave off the bottom of the heads which moves everything closer to the engine and you have to compensate other places, like shorter pushrods.
I like Darts, World or Brodix iron heads, you could even go vortec with the right intake but once they reach a certain HP they are done no matter what you do to them, I really don't like them because for what they achieve you might as well just step over them for real big gains.

 

The primary advantage of aluminum heads is their machineability - weight is just a side benefit. Aluminum heads can be serviced and repaired basically forever as the guides and seats are easily replaceable and the material is very weldable. The reason we see higher-tier heads only in aluminum is for the same reason - iron heads could be cast and machined to a similar level...but as the material is harder the tooling has to be too, and it takes longer...and who wants to pay MORE for an iron head than the identical one in aluminum?

Aluminum heads generally have thicker decks - not thinner. They don't increase CR at all, unless the chamber size is smaller...and generally they come in the same size as everything else for the GEN I SBC: 64 and 75/6cc. Valvetrain geometry ALWAYS needs to be checked any time a change is made.

Vortec heads are the best deal on the planet for engines targeting around 1 HP/CID, which is kind of the sweet spot for $/HP. Buying more flow (better heads) than what's required for a particular power target just ends up wasting money. No head produces power between their flow numbers, and it's a heck of a lot more expensive to machine heads to make more flow than it is to just buy the right heads in the first place.

 

From what I have read about the subject, pushrod length is alot more crucial with roller tipped rockers than with stock style stamped rockers, but a pushrod checking tool costs like 10-20 bucks, so you're nuts not to do it. It makes sense that if the pushrod is the exact right length, and the valvetrain geometry is correct, the rocker will push straight down on the valve. If the pushrod is to long or short, and valvetrain geometry is not perfect, the rocker will push down on the valve with a side load, which will wear out the valveguide, which lets the valve move around, which beats up the valve and the valve seat, then ya got no compression..........well, you get the idea. I'm kind of an old school guy who never worried about stuff like this back in the old days, (hell, none of us did) but it's the 21st century now, and I'm tryin' to get caught up!!


Scott

 

Cut out a cardboard box 18" wide and 4" high. Lay it onto the rear of your hood just like a heavy duty L88 hood would be. See if wifey can see over it or around it in her normal seating position. My guess is NO.

 

she actually sat in a 72 with the l88 hood and didnt have any issue with seeing out, she just didnt like the look of it.

 

I didn't see what engine you are starting off with to increase the HP but 350 gross HP is not that difficult to get to with a basic 350 as long as you can get the compression ratio to around 9.5-10:1 with the heads. There are numerous examples of folks on the forum with 350's with heads/Cam/intake/exhaust on OEM motors getting 300 RWHP which is easily 350 gross HP! You just need the right combo of parts to make it work.

Here is another example:

http://www.superchevy.com/technical/...ver/index.html

Note in the article that the 74 L-82 Net HP of 250 is 313 Gross HP. With very little effort, this motor made 415 Gross HP!

 

Take your existing small block and build it to 69-70 L-46 350hp specs. Aluminum heads not required. Will fit perfectly beneath the stock hood.

Zora Duntov is on record as having said the best bang for the buck was the L-46. He campaigned to keep it.

 

Thanks for all the feed back, I will be look at the various links and see if I can get my head around it all.

So the 200hp rating on the 72 was net which is RWHP? so on the forum, in general do people talk gross or RWHP (net) when they describe what their performance is?

I know that is probbaly a dumb question, if I even asked it properly.