Doom86

A good friend has a friend he works with who has a set of 601 casting heads that he wants to sell for dirt cheap. He told him that were "tapped for screw in studs" and mildly ported. What is the signifigance of "screw in studs"? They still have stock valves installed (1.84 / 1.5 i think) with "z28" springs.

If i get them i plan to have them ported and the valve changed to 1.94 / 1.6 . The goal of this car is to break into the 12's in 1/4 mile. Is it possible with ported 601 heads on a 350 block (others mods as well obviously)? I also have 416's that are on my car now if they will be any better.


many thanks for any help.

Rogue86

Screw in studs are just so with a high lift cam, you dont pull the rocker stud out of the head.

I dont think you can fit 1.94 1.60 valves in there. 1.94 1.50 is possible though.

They arent any better than your 416 heads as far as I know.

12's would be possible, but dont hold your breath. I ran stock 416's this year with a mild cam 442/465 214/224 @.050 in a 350 with all the mods in the sig. Only managed a 13.36 @100.49. The car also weighed about 3,000 lbs with me in it.

IROCaholic

You can fit 1.94 and 1.6 valves without any problems. I am using them in my 416 castings and I love them with my setup. Lookup a guy named sitting bull and check out his article on porting 305 heads. If you do every thing he has listed you should be able to break into the 12's with a properly matched combo. As for me I will be hoping to run about the same as rogue86 with my setup. Good Luck.

Doom86

thanks for the help you two.

Rogue86, if your running that with a stock 416's i think well ported heads matched with a beefier cam could get you into the 12's.

IROCaholic, thanks for the reassurance. Sittingbull's got some good info spread through-out these boards, i've read many posts with him spreading the 305 head knowledge. Good luck getting that iroc into the 12's, then you can mock the Z06 guys

im planning on going with the comp cams XE274H (flat tappet), which came highly recomended for a 12 second car, on this board and from a "speed shop" friend. Would it work fine with these heads?

i've already got hedman shorties (still in transit! )and next is a good 3" custom y-pipe and exhaust. For an intake im wanting to go with a wieand X-Celerator because its flow numbers match the cam perfectly. i'll be getting atleast a 2500 stall to match up.

thanks again for your help..

IROCaholic

If I were you I would actually look at the XE268 and a performer RPM air gap intake. Those 305 heads have great low lift numbers so they will benefet a little more from the smaller cam and that cam will match better with the size stall you chose. If you compare that cam and your ported heads to Rogue 86's setup there is no reason you shouldnt at least make high 12's. Good Luck.

IROCaholic

If I were you I would actually look at the XE268 and a performer RPM air gap intake. Those 305 heads have great low lift numbers so they will benefet a little more from the smaller cam and that cam will match better with the size stall you chose. If you compare that cam and your ported heads to Rogue 86's setup there is no reason you shouldnt at least make high 12's. Good Luck.

Rogue86

Yeah, now that I think about it, high 12's would probably be possible, but its going to take a lot of work. My car is much lighter and gutted than anything you would want to drive on the street. Its only seen a couple "street races" and thats about it.

I think with the work and $$ it would take to get 416 heads into the 12's in a relatively comfortable street car N/A, you might have wished you picked up some vortecs or another aftermarket head.

With the 4.10 gears and 26" drag radials I had to shift at 6k to go through the traps at 6k. Which i know is probably way above the power band of these heads stock. But I also was running a th350.

I did run an 8.34, as stated in the sig., but that was with open headers. The 8.34 should have translated into a 13.01 pass. But then again thats open long tubes, nothing you want to drive down the street with. The 13.36 pass came with mufflers on, due to the rules of the class i was racing in.

416 heads would make very nice street heads, and the low end torque they make would be fun on the street. Heck, with that mild set up, and stock suspension I could lift the driverside front tire a lil bit. But as for spending a lot of money on them with bigger valves ect, I kind of lean towards an aftermarket head.

This season I will be running a head casting that is VERY controversal on this board, and don't want to say more until I have track results, because of how set in their ways many people are about them. I am questioning the heads also, but only slips will tell the answer.

all is just my .02

Doom86

from my understanding in order to use vortec heads you have to have a roller block. The 350 is from a 71 truck, so it isnt. my knowledge is limited on all the different "toys" so correct me if im wrong here. vortec's were my first thought because we have a massive amount of junkyards here to pick through and they shouldnt be to hard to find, used.

i searched around and couldnt find anyone claiming 12's, or lower, with ported 305 heads. but then again the search engine isnt the best here.

i can get these heads for practically nothing, i'll use more money in gas picking them up then purchasing them. If having been tapped for screw studs and having been mildly ported makes them better(more cost effective) then my 416's i'll get them. BUT if they cant make the power i want then i dont want them. one of the heads is missing a valve, which is why he'll get rid of them for next to nothing. but if im having bigger valves put in this doesnt bother me.

ljnowell

You definately dont need a roller block to use vortecs, not at all. As long as it is not an lt1 or ls1, the vortecs will bolt up and work just fine.

Doom86

sorry if this is ignorant (yeah, it is ) but dont you need a roller block to use a roller cam? I always thought vortecs needed roller cams. always good to learn something new. thanks bro..

Rogue86

No, you dont need a roller cam to run vortec heads. They will work just fine with your 71 block.

SSC

I wouldent. Comp doesent recomend a engine with over 9.5:1 compression with that cam, you will be well over that even with stock pistons.

IROCaholic

He can always do what I did with mine and open the chambers up a couple of cc's.

Stekman

A roller cam, in and amongst itself merely refers to the mating surface between the cam and the lifter. A flat tappet is just flat, whereas a roller has, well, a small roller, that, well, rolls along the cam lobe surface. There are a few consequent facts to the roller setup, however, the core idea is the fact that there is a roller built in to the tappet that eliminates friction between the cam and the lifter.

That said, the fact that a block is a "roller" block means that it is a block that the factory has set up to house their bastardized roller setup. Since a roller lifter needs to be kept square to the cam lobe, a method of "centering" the lifters is called for. In the better setups, a simple link bar joins the intake and exhaust lifters for a cylinder. In the factory roller setup, a dogbone-resembling retainer is placed over the 2 lifters, and then a hold-down plate is bolted by means of 3 bolts running along the center of the lifter valley places pressure on the 8 dogbone retainers to hold them in place. Also, a cam retainer plate is bolted to the front of the block. This plate holds the cam in and prevents ot from walking forward (cam walk). That's the long explaination. In short, a roller block is nothing more than a block that is cast with provisions for these "extra" features.

If you do port the 601 heads, as far as the chambers are concerned, you will be doing chamber clean up and deshrouding, which will take the chamber volume up a few cc's or so. In the end, after proper work has been done, it won't be too terrible. 60-62cc's is achievable after proper deshrouding for larger valves and cleanup has been done.

Stekman

Stupid reply....let's see if it actually goes "to the top."

Doom86

Thanks for the help you all, much apprietciated.

Stekman thanks for breaking it down for me. i like to here how and why, rather then just yes or no. I think i may actually pass on these 601 heads.