hey guys i wanted to know which of the following heads will give me the most hp #'s?either the 416 older tpi heads or the 081 which are the center bolt heads.i dont mind about the bolt pattern for the manifold being diffrent.i'll just buy one for the right application

 

I believe they are identical except for the four center bolt holes. If they are for you '89 I would go with the 081's they will match up better.

I used the 416 and wish I had used the 081's just because altering the intake manifold to fit was a pain.

 

i dont care about the manifold issue

 

if you don't care about the manifold, go with the 416's then.

 

....or get a set of World Products S/R Torquer 305 heads. They're just about the only somewhat performance-oriented heads built for the 305.

A more expensive alternative would be a set of aluminum L-98/ZZ-4 heads.

Also, some people have put Vortec heads on their 305. There are some "gotchas" with them like the chambers are bigger than a stock 305 head and will lower compression and there is no exhaust crossover to keep a stock EGR system functional, plus some possible valvetrain issues, etc.

 

One of the mags did a vortec build on a 305 i think they just milled them down a little to get th CR to a more usable area.

 

The 416s, and 081s are pretty much the same head with the exception of the center intake bolts. Which to get???? Whichever you looks to you like its in better shape, as they are both going to have quite a bit of use on them.

I have 416s on my 350 right now. Stock, they flow within a few cfm of the iron L98 heads, which flow within a few cfm of the aluminum L98s. The are quite impressive with some port work by the way. There are several guys here that have flowbenched them and have gotten from 220 to 235 cfm (if I remember correctly) on the intake side, and 185 or so on the exhaust. I've seen ported aluminum L98s which flow a little less than that.

 

What kinda cam are you going to run with the heads? The aluminum L98 intake isn't so hot but it has a great D shaped exhaust port and is out standing for a stock head, so much so you can over do the exhuast on a cam and lose power, also are 58cc, down fall is cost. If you need to do a valve job get new valves and springs you might as well get the S/R torquer 305 heads and be ahead of the game.

 

Here's a link to azvolfan's 416 swap. You'll see what he meant by the manifold issues...
https://www.thirdgen.org/techbb2/sho...hreadid=267649

Bruce (90RS305)

 

If you dont care about the manifold, I would go with the 416's...
Roller rockers and valve covers are more plentiful and cheaper for perimeter bolt heads.

 

If you run roller rockers, keep an eye on your valve lift. Anything around .460 to .480 requires some attention. If you go too high on lift, you can have a retainer smack the top of the valve guide. If you have that problem, you need to get the guides machined down some.

 

But if u run 1.5 ratio RR, it maintains the same lift as the stock lifters.

 

I'm running 1.6's with an '87 L98 cam. Does that sound like it could be a problem.

 

well right now i have the lt1 cam and i am planning on putting 1.52 rr. they say u will still gain some out of the 1.5

 

If I am not mistaken, the 416 heads can run the LT1 cam and 1.6.s but you need new springs that can handle the lift. The reason I probably did not need them is that I used the L98 cam.

 

i think if i get a new shop, i'll just buy the sr torquers. i know a guys who makes over 240 rwhp, 248.6 rwhp to be exact with stock fuel system just higher f.p.