I have a 74 that's in good shape. It's not numbers matching, but a really good driver - better than most that I have seen around my neck of the woods that have been passed around to about fifty different owners without much love. This is not my fist rodeo and to be honest, this car didn't just fall out of perfection from the sky. As a general of thumb, no matter how pretty it looks, no matter how shinny the paint and how many new parts they put into it, you're gonna end up rebuilding the car. Even though I knew better, after my heart said buy it and my head said walk away, it took awhile to get it to where it is.

Okay, story time over. Now for the meat and potatoes. I'm thinking about updating the basic 350 short block they put in the car when I bought it with a mild cam, AFR 195 heads, Intake & EFI conversion. It has less than 1,000 miles on it and runs strong, so I'm not concerned about it coming apart if I bump up the power. Yeah, I know, it all depends on the integrity of rebuilder and it would most likely be a lot cheaper and less frustrating dropping a create motor between the rails; but it's a running well put together car now and I don't want to bother with hunting around for fixes during the install that tend to crop up.

The first question I have is about vacuum in relation to cam lift. I have no idea what's in it now, but I assume it's more or less mild to stock. After I blew up the Turbo 400 a month or two after I bought the car, I had it rebuilt to old-school three-quarter race and bumped up the torque convertor to 2400 to match what I thought would be closer to the cam. Big difference. It really chirps the tires with authority when I jump on it. But I want more. How big of a street/strip cam can I get away with and still have enough vacuum to power the brakes and the lights? This would be something that would be related to the intake as well. How far can I go?

Next question. I like the AFR 195 heads. They're pretty close what I have on there now, only in Aluminum with bigger 65cc combustion chambers, more refined. Mine of course are cast iron with smaller 58cc combustion chambers I think. Would I be better off with something else? Would bigger combustion chambers hurt me if I'm looking to maximize low-end torque? How far can I go?

What about the EFI conversion? I still have the original distributor with cable driven tach drive. It's been rebuilt and converted to electronic ignition and I see no reason to replace it. Will I need to get an MSD box to pick up the tach signal for the EFI or can I pick it up from the ignition coil or some place else? What would be the best EFI conversion kit for this application?

 

The FITech EFI requires a MSD distributor

 

That’s not true. You can run the stock distributor but you would need an MSD Box for the Tach Pickup. I did it exactly this way. If you do get an MSD Distributor and phasing rotor you can use the FiTech to Control timing.

 

Don't know of an iron head with a 58cc chamber. Unless your wanting to do higher then hydraulic cam rpms not mild cam, the 180 head afr flows more air then you will need. Compression always equals more tq. So you want to use as much compression as your fuel will allow.

 

Cab1..I am close to you in Tiverton.



OEM L-82 block, L-82 Rods, L-82 Crank, JE Forged Racing pistons/rings, Howards Roller cam (.525/.525 lift, Duration 219/225, LSA 110), .030 bore, new oil pump, new Fuel pump, New Harmonic Balancer, AFR 180 64 CC aluminum Heads, .015 head gasket, Total compression 10.2:1, Ported L-82 aluminum Intake, Holley 4175, 1 7/8 Long Tube header, etc.

Goes like stink...................And looks like an L-82...................but a 355 with about 150 more HP than non emissions mildly stock L-82!​​​​​​

 

OP

IIRC ... OE GM Iron 305 aka 5.0L heads are 58cc but have very small valves. Also, OE GM L98 and ZZ4 heads are 58cc but are all Aluminum.

You truly need to KNOW where you're at before you buy more stuff.

get the OE GM head casting number from underneath the valve cover

get the block casting numbers ... you need to verify if you have a 350ci or 305ci or 400ci ... top rear of block driver side ... just aft of driver head

be really nice to KNOW which pistons ... dished or flat.

JMO ... but if Block is a 305 ... I wouldn't spend time & $ on it ... 305's small bore inhibits flow from any good head
FYI, many a low-buck builder has stuck 305 heads on a 350 to jack up compression ... they sure will ...
... but teeny valves don't flow worth a flip ... they run out of breath by about 4500

 

cardo0, read post 5 again. You misread.
He likes AFR 195 aluminum heads..
Has iron heads.

 

Have them flat milled to make your cc smaller not a big deal just measure pushrod length...youd have to do it anyways.

 

Sounds as though motor may have 305 heads ... as before ... casting numbers will tell the tale.

If ... if motor has a 305 block w/ its small (3.736") 305 bores (even smaller than a 283) ... any T&E beyond affecting repairs is tantamount to polishing a turd ...
... if 305, begin looking for a later 350 roller block/core etc.

 

Those 305 heads gotta go. Ignore the people that rave about them, higher CR what some talented porter did after sinking tons of $ into them they belong on a stock van or the trash bin take your pic.

 

AFR 195s are too big for a 350/355......only if you intend to go 383 later would i use the 195s over the 180s

 

Cardo0;

Of course it makes sense! Read the damn post! I never said AFR make or sell iron heads! I said the heads on my car are iron heads! This particular car was born with an L48 - ergo small heads with nothing to offer in performance and I know these heads have combustion chambers smaller than 65cc. I was trying to get a rough compassion between what I have and what I would gain out of a set of AFR 195cc Eliminator Street Cylinder Heads - which is a far superior well-engineered aluminum head with very good flow. My only concern is the size of the combustion chambers. You can buy aluminum heads in several different combustion chamber displacements and bigger is not always better. I was just trying to get an idea if 65cc would be a good fit for what I have, which is basically a dead stock 350 or is there something better. Jesus Christ! What is it with these boards? Why does everything have to turn into a shouting match with neurotics?

 

Nobody knows what you actually have for heads - not even you! And you definitely don't need my help so I will delete my original post.
Enough of your nonsense questions and information. I'll let others enjoy your attitude. Maybe it's not the forums that are neurotic but it's you. Your the one doing the shouting!

 

Whatever head you decide to go with wont hit max potential with your stock L48 cam and its low lift numbers

 

I guess I have a lot of work to do before nailing anything down - probably in the Spring. If I had the money I most likely would go the way of an LS3. There are outfits out there that can put together a package with pretty much what you need, but not everything, and it can get expensive real quick. There's always something you have to monkey around with to make it work - like the oil pan. Anyway, thanks to all for the input. I'll be watching and learning.

I came across some old pictures of my old 66 that I had put together many years ago when I was a kid. I wish I still had it. I bought it for $2400 from a guy that was trying to restore it, but ran out of money. I brought it home in a basket. Everything was there, though. It had a nice little 327 with a 750 Holly double pumper on a Tarantula manifold. I put headers with pipes and shields on it and it really woke it up. The only bad thing about it was the kid stripped all the paint off the body with a grinder. Anyway, I got it together as best I could with the limited resources I had while in college and It turned out to be a fun little driver. Then one day I was rolling down the highway, doing about a buck, when I pulled a valve train stud out of the head and that was that. I thought I had killed it, but I was lucky. I took all the pieces to a machine shop (Bradwell & Hallaway) and everything was good. I had it magnafluxed, punched out thirty over, line bored, decked and paralleled, polished the crank, cut the bosses and had screw on studs installed, shot peen the rods - you name it. I was amazed at how good it came out. I wanted to do something special with it. Why not a blower?

I've been trying to put some pictures here for an hour, but it's not working right. I'll try to put in a post below.

 

If you keep the duration under 220 or so you should still have great vacuum. I like JBL82s Hydraulic roller.

 

If you have the stock L48 heads they are well over 70cc?
Regardless its going to be a real nice upgrade. Dont overlook their 180 head its perfect for a st 350.

 

Correct^^^^Leigh......I have very high vacuum and no issues with power brakes or the headlights...you would never know that it is not the OEM L-82 cam....from the vacuum.

 

let go of that button ! lol