74-Roadster

Tired of the dog L48, but since I'll be going fo a new engine in the rebuild, anything I spend now will be money pissed into the wind. I need something used and cheap to make the engine breath better, any suggestions? And estimates of used cost?

Thanks :seeya

cardo0

Read that 1.6 rockers with good intake (Edelbrock peroformer), headers, good ignition timing can get close to 300 Hp (well maybe more like 280). Too much work to replace camshaft if your about to rebuild. If you really have the need but don't have the $$ - rebuild the stock heads with 3 angle valve seat and mill off some for more compression. R&R heads I think is much less work. Use the Felpro .015" steel shim head gasket. I have to say it, use umbrella valve seals (because stock o-rings stuck so bad). ;)
Good ignition and headers should set up your shark for a Hi Po rebuild. :hurray:
My estimate for the works ~$700. :skep:

Crash Dummy

74-Roadster....

Why waste the money? If you are intent on going with a different set-up, just sink the money that way. You did notice I said *sink*? That's where the money will be going. :lol:

mountainshark76

Latter model 305 heads help a lot they will raise comp. ratio. 1. to 1.5 and flow ok, other wise mill yours to the max and uses steel shim gaskets with 1:6
rockers it helps good headers :D

tnt76vette

There are 2 or 3 outfits that sell rebuilt #416 heads (305 HO) but with 2.02/1.6 valves, on Ebay all of the time. I got mine from a company in Houston, TX at a cost of 365 bucks (+ shipping). They are 64cc so they raise my compression up to 9.5 or so. All new springs that are good out to .510 lift, and new swirled valves, guides, etc. Mine are on and running, just waiting for the damn weather to warm up here in MI............ :cheers:

nunus79

Buy the heads that you plan to run on the rebuilt motor. You can get an idea of how that head will perform on the new motor by running it on the old. Buying the heads now will also lessen the wallet shock when it comes time to pay for the rebuilt shortblock.

Small chamber aluminum heads, like L98 C4 heads, would be something to consider too. Good luck!

81ZZ4

New cast iron Vortec heads from Chevy are great. read about them.
Very reasonable.

Smitty's75

Look for some "186" heads on E-bay,,same as the 70 LT1's but have accessory holes. Good flow & raise compression 1.25 points or depending on head gaskets.

74-Roadster

New motor is 2-4 years away and I won't decide what setup until I've pulled the body. Not to mention I couldn't tell you what I'm going to run yet . . . I'll decide that closer to purchase time and probably after I'm getting the rolling chassis ready. For example, I may go with an LT-1 from a 90's Vette/Camaro. I may get a crate motor. If I go with C4 suspension I may opt for an LS-1 block. So, the odds are very high that any heads I buy now won't work with future plans. And if I stayed with the old 350 block, I'll probably run some high end AFR heads and there's no way I'm putting that kind of money into a tired L48.

#416 305 heads sound like a good option. I want something that'll flow better and up the compression. Adding 50-60 HP would sure feel better and later in the summer I'm thinking about swapping the rear end for higher gears. Just something to get me off the line better. The car looks so cool and if I'm gonna end up driving it for another year or two before she comes apart, she's gonna have to run a little better.

Thanks for the tips! :cheers:

Ganey

You will not get 50-60 w/ a little more C/R, intake, 1.6, etc...
If you really want to get close to 300 HP, then CAM & rebuild & mill the heads you have.

:cool:

fauxrs

Hmmmm - good flow 305 heads? - never heard of those - not sure i believe that.

1.6 rockers. this will give you about a max of 10-15hp -Maybe- depending on if the heads flow better at that lift than they do at the factory lift - many heads dont - especially factory iron heads. If your heads are flowing as good as they will then no amount of extra lift will make much of a difference.

Many mags will test higher ratio rockers with high dollar aluminum heads or heavily ported iron ones - and yes they do get sometimes as much as 30 hp. bolt those onto factory iron doorstop heads and the change is much much lower.

You can deck the head to get another pt of CR - 1 pt of cr is good for about 1 tenth of a sec in the 1/4 (rule of thumb YMMV).

If you buy lt-1 heads w/ or w/o accessory holes you will be spending probably about as much as if you bought a pair of Vortech heads (which outflow LT-1 and fuelie heads anyway) especially if you have to rebuild them.

Vortech heads will be your best bet if you are thinking heads only.

Otherwise, Ganey is right on the mark - you want a new cam - with those new heads to get real benefit from your buck.

74-Roadster

Thanks for the comments! :cheers:

I got the same story about the 305 heads from the engine builder in our local Vette club today. He said the 305's won't flow any better than my heads. He agreed that Vortech heads are the best low-buck option but then you have to buy an intake as well.

His suggestion. Decide what motor I'm gonna go with and if it's based on the 1st gen 350 block, get some good quality aluminum heads that I can use on later on, otherwise forget it and leave everything alone.

:( :( :( :( :( :( :( :( :(

I really shouldn't even be thinking about spending interim $$$ but I'm sick of not being able to light 'em up. Was hoping to hear, "get xyz heads for under $300 and change rear end gears and you'll have a blast. Oh well . . .

Thanks again. Guess I beeter stick to fiberglass and painting. :lol:

1st time

if you have 1500 to spend u should call donnie at dream chassers in am tx
he can get u 300 hp and for a little more more hp awsome guys thay build our race engines