scoflaw

iTrader: (2)

Just bought a 88 GTA 305 TPI. I originally planned on hacking, on it, to get some more power, but when this car arrived I could not believe how clean and bone stock original it was.

Way too nice to alter. Still the power it makes is pitiful compared to the other vehicles I own. Any ideas on what I can do to this motor and retain the stock appearance? It could use another hundred horse

DeltaElite121

pull the boat anchor 305 out and put a well-rounded 383/406 in if you've got the budget for it. Getting 100 more out of a 305 is going to take some work. We've had a few people on here do it with great success, but I personally wouldn't want to be working with a massive restriction like a 305.

NufNuffZ28

iTrader: (10)

-small cam
-ported manifold and plenum
-quiet high-flow exhaust
-roller rockers
-ported TB
-High flow air-filters
-headers(if you don't mind them being on there)
-stall converter
-hidden nitrous
-bump timing to 10

Damon

Agreed- cubic inches with decent heads on top (like aftermarket aluminum heads painted the same color as the rest of the engine) is your shortest route to "stock-appearing" victory. You should even run a super-mild cam so it sounds stock out the pipes and will play nice within the limitations of the factory TPI setup (no high RPM intentions- just good breathing in a modest under 5500 RPM powerband).

... Or nitrous, like Nuf said, above.

scoflaw

iTrader: (2)

Bigger inches and better heads. I'm OK with that, want to work retain the stock exhaust manifolds, and TPI. Power killers no doubt. What about the computer, EGR and the rest of the BS attached. Don't want to hack stuff off
?

Damon

You'll need bigger injectors and a custom tune in the chip- but those are not "visible" changes.

If you get heads that take the 87-up intake manifold bolt pattern (not all aftermarket heads offer this option!) and have an exhaust crossover passage, all the top end stuff will bolt right back on and the EGR will work.

If you go with heads that don't have exhaust crossovers you can turn off the EGR system in the chip anyway (since you're going to have to custom program it regardless) and it will still appear stock, it just won't be functional.

If you go with heads that use the more common 86-down bolt pattern you can modify the angle of the 2 center bolt holes in the lower intake to accomodate that, but it's a bit "ghetto" and won't appear factory upon closer inspection.

If you want a total bolt-on, something relatively affordable like the Edlebrock Performer heads for 87-up bolt pattern is as easy as it gets. They are not the best performing heads on the market, but they're quite a bit better than stock and, beling aluminum, they shave about 45 lbs. off the front of the car. Top-shelf heads (still available with 87-up bolt pattern and exhaust crossover) would be something like a set of AFR heads, but they're more bucks, obviously.

I'm not up to date on all the iron performance heads available these days but there are undoubtedly some that would also fit the bill if you look around.

Somebody is going to jump in here and suggest factory Vortec heads, but I wouldn't do that. The conversion is more costly than just the heads. They require a pricey $400 lower intake manifold (from Scoggin Dickey) which drives up the total cost into the same range as just bolting on better performing aftermarket heads that will work with your stock intake.

scoflaw

iTrader: (2)

Damon, thanks for that info. Was thinking about a cheap Scat 383 rotating ***. with maybe some corvette 113 heads???? Will D port exhaust work with my manifolds?

Damon

Yeah, it will, but those heads don't have an exhaust crossover or the same intake bolt pattern as your current heads/intake. And there are better choices out there if you're willing to put up with those annoyances.

scoflaw

iTrader: (2)

Is there an aluminum GM head that could work for me? Not looking to spend a fortune

Damon

Um.... no. Nothing I can think of that has the 87-95 bolt pattern and exhaust crossover.

I suppose you could spend some money having your stock heads fully ported by a professional head porting shop. At least you KNOW they will fit and work! And the port work won't cost you as much as a set of aftermarket heads will.