Ok so i know people are gonna start with why do this but just humor me in helping me out with what I am thinking of doing with a 305. I have a 1982 trans am and just swaped a 5 speed into and the motor is bone stock. The 82 305 lg4 i believe has the 416 heads which I was going to get milled .02 to up compression and throw 1.94 intake valves in. Then for the cam I was goin to do the jegs comp cams EX268 cam kit with springs and all. Then a performer intake with a good q jet carb and good hei. So my questions are is this a good setup? will it work ? is that too big a cam? Thanks for the advice

 

Start with exhaust, then headers, then a Comp XE256 and let the heads wait until you try that.

 

thanks for the input but everything is apart and i was really looking to do everything that I had in mind now. So still just curious about the build I had in mind and what you guys thought or what advice u have about the setup i was thinking. Thanks

 

While the motor is out... buy a 350.

 

Before you build iot your way, before you do any assembly or reassembly, is THE time to replace un-wise parts selections with better selections. A great many of us have sunk money into the 305, each of us thinking we had the recipe for making this underdog really great. Not saying you can't make a 305 not-disappointing, at least for a while, but all of us who moved on to 350s all agree, the 305 just doesn't have the potential. Dang few 305s are even worth having, since except for a few low-mileage, rare-options examples, 305s do nothing for the value of the car. In theory, a 305 can be built for better MPG than a 350, but that's not the goal here. Getting a useable 350 short-block assembly from a salvage yard is can be done for $200 in all 48 states, and can get through the emissions inspection in all 50. Finding a useable-as-is 350 isn't difficult. Getting it running in place of a 305 is no great challenge, either. But for those of you who insist on playing with a 305, what's the point in asking us if your mind is already made up, and you just want approval? To get approval, make wise selections. If you haven't yet run your wrong cam, return it and order a right cam. The cost is about the same. Close enough. Already had the heads cut for bigger valves? Say so, we can help you get a cam you'll regret less. If you're going to do it at all, do it per the advice of those who've been down this dead-end road.

 

ok i understand what ur sayin and i have not bought any parts for this yet i was just curious if my setup was a good one. and what i got from u is i have the wrong cam choice anyways. so lets just say i mill the head down for more compression it will be cheap i work at a shop and we get deals with our machine shop. then throw the ex256 cam in throw a intake n headers at it

 

Just to make one thing clear, local speed shop here circle races a 305. Brodix heads, 10.5:1 compression, solid tappet cam (.510" lift) turning 8k rpms makes 530 horses. He has made it clear he could get way more power out of it if they didn't limit his lift, valve springs, or let him port the heads.

But I don't think you want a solid tappet cam or turn anywhere near 8k rpms.

 

What people do in round-track racing is not a guide to what should be done on the street. Don't even TRY to go there.

The thing to understand about that kind of racing is, he doesn't run a 305 because "it's a good idea"; he does it because IT'S THE RULES. Kind of like, the NASCAR guys use 350-ish CID and don't run bored and stroked tall-deck 400s; not because they're "faster" or "better" somehow, but because, IT'S THE RULES. That's how they keep the cars slow and equal. Kind of like classes I used to build motors for, where THE RULE was for example, they had to use a Holley 4412 2-bbl; not because that's such a "good" carb, but because it acted as a "ceiling" on the speed, and by extension the cost, of those cars, and even more than that, limited the ability of someone to come in and spend their way to victory. In fact I recall one of those classes that was a "claimer" on the carb!! Or, one that had a rule that the valve lift couldn't exceed .390"/.410" (the 929 cam specs); it wasn't because the 929 is so "good", it's because IT'S THE RULES. Or yet another that required 1.25" springs; any cam you want, any heads you want, just had to be 1.25" springs, which meant that anything you jammed in there over .500" of lift, meant you might not finish. Or yet another "bomber" class (this one wasn't worth building motors for) that the ONLY rule was, the right rear tire HAD TO BE a F70-14 (yes it was a long time ago); it wasn't because that's such a "good" tire size, it was because if you're running a 74 Monte Carlo or something with that on the right rear, nothing else about the car matters at all, it's PURE DRIVER at the finish line. One kind of class I refused to build motors for was a "claimer" on the motor; had like a $500 "claim". The guys with junkyard sponsorships DOMINATED that class and there wasn't much anybody else could do about it.

Anyway...

With a 305, IMO anything above the head gasket, plus the cam, is fair game... you can spend as much money as you want on it, and AT LEAST, when the disappointment of REALITY sets in, you don't have to throw it in the trash and start over. But DO NOT TOUCH THE SHORT BLOCK!!!! Because whatever you waste on that, DOES have to go into the trash when you learn THE TRUTH and have to start over.

I wouldn't "throw" parts into anything. I'd make a point of properly installing them. WHich in the case of large valves into 305 heads, would involve conisderable port and chamber work. But for a 305, it's not at all necessary.

The XE256 is known well and widely to be a good cam for the old low-compression garbage LG4s from the earlier years of these cars. But even that won't accomplish much without getting rid of the exhaust, EVERY PIECE from the heads to the bumper, and putting something bigger than a drinking straw on it. That should be THE FIRST mod to a LG4. The Performer intake is a waste of money because that's not the bottleneck. Same for the carb. Leave it alone and concentrate on where THE RESTRICTION is.

 

Thanks everybody for the input and i have learned a lot but just one last question if i do take the stock 416 heads down .02 will that be ok to do as far as clearence on valve to pistions with the 256 cam and 1.6 rockers

 

use the 268 cam, with the stick shift you have any stall speed you want to get in the power band.

If you can find vortec heads mill them down to get 9.5cr and put a performer rpm intake on it. If you get to far in the 416 heads you could be at the price of new vortec's.

Do the 416 even have harden exhaust seats for unleaded fuel? In 88 my 454 crewcab dually 4x4 only has chemically harden seats from the factory.

I'm doing a 305 too....cheers

 

I agree with only doing anything to the 305 above the head gaskets and cam. I also have to say that upgrading a 305 you already have is going to be cheaper than buying a new short block and then upgrading it. I'd say for a 305 if you're just looking to make it a bit more fun and don't want to go through the hassle of a swap, then by all means go for it!

 

yeah i was thinkin more towards the vortec heads to but im trying to keep a budget and just use the heads i have so any tips for me there. yeah guys more power to ya for building the 305 i mean we all know about how mw66nova had one wicked 305 there for awhile. so they can make decent power