So, I bought my new GTO, and I'm feeling really guilty now looking at my 1986 Trans Am sitting there, without a spot of rust on it, not moving... I started this project quite a while ago now, and I think it's time to finish it.

It currently has a 3.42 rear end from a 1997 formula in it, along with energy suspension bushings all around in the rear. The rebuilt 700R4 trans with Trans-Go shift kit is sitting in the garage, ready to go. I need to run new brake lines to the rear and put the new brakes on. Fronts are ready. I've currently got the stock heads(14014416 casting), with new springs and seals, ported out a bit. I've got a 1974 4-bolt 350 block sitting in the garage(casting 3970010), with a 3932442 crank(lots of surface rust, maybe no good). I've got Mallory 110 series electric fuel pump, and an old Edelbrock Performer intake. Stock carb, and all the stock accessories still sitting around. 1.6 steel roller tip rockers, and flowtech 11102 shorty headers(bleh). Lots of parts that were given to me, or got cheap.

I'm trying to decide what to do here. I'm looking for decent power, but want the car to be completely streetable. I'd like to do this with as little money spent as possible(the Goat is costing me, and gas at almost $4 a gallon sucks), but would still like her to be moderately quick. I'd love to reuse the heads, since that would save a lot of cash, but it might not be possible. With the higher gearing, and the 350 block, those heads probably wouldn't give me enough top end. Though, I'm sure the torque and low end would be bad *** with the high compression. It would scream 0-60, but after that...I dunno. lol I'm also concerned about the stock carb. Probably won't be able to reuse that thing.

So, thoughts, suggestions? I really have no idea what to do with her. heh

P.S. Not concerned about being faster than the GTO at all. Just want to get her running, and be fun to drive.

 

I had just finished up a nice build similar to yours.

Due to shortage of coin, I used 081 58cc heads.
(very similar to the 416 casting) I used them on
a L98 block. Reused stock valves, new springs,
retainers, seals and 1.5r roller rockers. Alot of people
here on Thirdgen have walkthroughs on porting both
the 081 & 416 casting heads. To take advantage of
the topend you specified, bigger valves are a must,
and obviously alot cheaper than buying another set
of heads.

There isnt much difference between your '74 block
and a later year casting.. Other than the benefits
of a roller cam.

With what you got, I dont see why you couldnt build
something streetable and be able to give that GTO a
run from a dig.

I think those 416's on a 350 with some 3.42's and
a subtle stall would move nicely

 

Yeah, I was thinking that as well. A link to the walkthrough for porting those heads would be awesome. I'm not as familiar with this site as I am the GTO forums, so it would probably take me forever to find it. Any suggestions on cam and bottom end? That's my major question, since that will be my biggest cost. The ignition and carb question is still up in the air as well. Going the route I am going, I probably want to completely ditch the stock ECM controlled stuff and just get aftermarket, no? It's been a while since I worked on her, or did any research, unfortunately, so I'm way out of the loop, and I know this has probably been done 100 times by now.

 

I run modified vortec heads (Manley valves, cut seats, race valve job) and a Crane cam on my 355. For the $$ I have in it, the motor is pretty mean. I had it in a mud truck and its going in my 86 Camaro with a nitrous plate until my big block is finished.

For the money/power I think its kind of hard to beat vortec heads.

 

I'm trying to stay away from buying heads. I'd much rather port my old heads, throw some bigger valves in there, and strap them on. From what I've read, I can get real close to the vortec performance out of the stockers. I'm trying to find a good walkthrough though.

 

416 casting 305 heads are equal to 083 casting 350 heads in all ways except chamber size and intake valve size (and details like intake mount bolt angle and valve cover bolt type - and, 081 castings are the same as 083 castings in those respects).

Port the 416's, have 1.94" intake valves installed (and 1.60" exhaust valves if you really want to improve them), unshroud the valves, which will increase the chamber volume, and pick your piston dish volume accordingly to get the compression ratio you want.

It's a sound plan. Vortecs have the advantage of a slightly better chamber design, but you're right - you can match them flow-wise with ported/bigger-valve 416's.

 

Yeah, I was definitely going with the 1.94" intake valves. The 1.60" exhaust valves will go in as well, depending on funds(they tend to be quite a bit pricier). I'd like to shoot for 10.9:1 or so compression ratio, and throw a nice sized cam in there. Something with a nice lopey idle.

If I tossed on an aftermarket carb and vaccum controlled distributor, eliminating the computer controlled stock components, what would I need to do with the transmission? Just get a bracket for the TV cable, or is there something else I need to worry about with it? I figure I'll register it as a show car, and being more than 20 years old, I don't think I need to worry about emmissions, so no cat to worry about.

I figure with the shift kit, the 3.42 rear end, and a decent bottom end, with the rebuilt stock heads, the car will really move. I'm debating on getting the motor ported over, as well. The issue with that, is that it gets much more expensive.

 

go to enginkits.com, they got a set of 1.94 valves for $26, probably can make you a heck of a deal on 1.6s

 

You will need to get the geometry for the throttle valve cable correct or you'll burn up your new TH700. If you go with a Holley, a "corrector" bracket is available to bolt onto the throttle arm. A stock cable housing bracket should work. You will also need some means of locking up the torque converter - there are kits available from Summit, Jegs, TCI, GM.

You'll also need a torque converter that stalls higher than stock. Depending upon the cam, 2500 RPM stall would be minimal. That's what I'm running in my fairly mild daily-driver, and it would like even more at the track. Works well on the street, though.

What besides the heads were you thinking of getting ported?

 

Here's a highly reccomended and very detailed
article/thread by Sitting Bull here on Thirdgen:

https://www.thirdgen.org/forums/tech...-pictures.html

That should help out if you decide you run the 416's

 

I'm running ported 416's on my 350. Works pretty good. I should have used more cam though, this is quite tame with the xe268.
I have 10:1 CR. With a 0 decked block and .040" quench it'd be at 10.3 or something. Anything higher and you need pop up pistons, or a less aggressive chamber porting job. I'd go with neither, a hair over 10:1 is perfect, too high and you get knock or you'll need race gas.

That stock carb is fine, save your money for something that'll do more good - like headers.

 

Personally, I'd keep the stock carb and ECM, and just re-jet and adjust as necessary.