AronZ28

I raced a guy in a black 86 Trans Am GTA. I got a quick glance under the hood and he was runnining the stock TPI intake and headers with an auto tranny. He claimed it was a 350 that he had rebuilt and hinted that it had been bored out or stroked. Anyways I absolutey whooped him past 50MPH and put 3 or 4 carlengths on him when I shut down at 130. I figured he would have given me a good run for my money if he had stroked it and it was a 350.

Now that I look back on it, he could have been running a 305 and bsing me. Do the TPI 305 and 350 look the same, or does the 350 have a bigger block?

87DJP2001

Since there is No visible difference, most people will say its a 350. This goes 99 44/100% for sellers also.

V8Rumble

If he said that it was an '86 GTA, he was either BS'ing or misinformed... They didn't start to make GTAs until '87...

thezisking

That'd be an EXTREMELY rare car that should be kept 100% original if he was telling the truth...considering they didn't make GTA's until 1987 and there were only 50 (I think) 350 TPI cars in 86. I love it when people try to BS you and you know they're full of ***t! Plus... You made him look stupid by smokin' him too.

bmillington

Isn't there something about the red line on the tach. I remember that my 305TPI was lower than my 350TPI. I know its something about the cams.

Ucantcme57

If I used a stock TPI Intake, you wouldn't know I was running anything other than a 305....

You would have to look pretty hard to find that the GM and it's number is not there, instead is Motown.. Would you be able to read that at a glance under the hood?

krazzycowgirl

Ok Get the story straight you guys.
Yes the GTA didnt come in to play until 1987 Along with the 350s (there WERE no 350s Produced for sale in 1986)

The 50 1986 350s that thezisking is talking about were test mules only & only produced in the CAMARO not the Firebird line up.

The guy was BSing you Aron But he could be wrong on the year of the car as well. Go over check the Vin code The 10th Digit of the vin is the year it should be a G if its an 86 & a H if its a 87 Also the 8th Digit is the Engine code.
86 Engine codes:
2 = 4Cyl TBI (Iron Duke)
S = 2.8 L V6 MFI (TPI)
H = 5.0 L V8 4BC
G = 5.0 L V8 4BC High output w/ MT
F = 5.o L V8 4BC MFI W/AT (TPI)

87 Engine Codes:

S = 2.8 L V6 MFI (TPI)
H = 5.0 L V8 4BC
F = 5.0 L V8 MFI (TPI)
8 = 5.7 L V8 MFI (TPI)

thezisking

If you have a complete 305 TPI and a complete 350 TPI sitting next to each other (NOT in a car...on the ground or hanging from a hoist etc...), how would you tell them apart?

87DJP2001

Out ot the car, just check the casting numbers.

thezisking

Where are the casting numbers? Will it say 5.0 or 5.7?

87DJP2001

Try doing a search for the location and meaning of the numbers (Mortec) or are you that helpless.

Ucantcme57

Some say 5.0 some say 5.7 some don't say at all the thing is you probably can't see the flat part or the flange to the bellhousing of the transmission. That's where the numbers or 5.0 or 5.7 is located. older blocks said on the driver sides I think...? The fact is without getting the numbers off the block or extracting the heads, and the crank.. measuring the bore and then stroke.. Besides that way you will never know. some crazy person could really bore out a 305 and put in a 350 crank dosen't that make a 377 or something? You could go bigger than 427 with my block. Bill Mitchell is making 454SBC motors, put a TPI on it and you wouldn't know it from a 305 or a 350..

92RS305#2

i think the biggest small block possible is 472ci, can anyone verify this?

Ucantcme57

Fel-Pro recently introduced PN 1036 gaskets with a 4.250 gasket bore. Combined with the 4.000-inch stroke, the World Products 454 small-block has the same bore and stroke combo as an original 454 Chevy big-block. but in a small block. So you cannot get a larger head gasket than 4.250 and I haven't seen any cranks with larger than 4" stroke I could be wrong.. So I think you would be at the top with a 454.. That's with a 1.425:1 Rod to stroke ratio.. maybe in the future you might can follow bill mitchell I am sure that they will be following this and they will be making larger cranks sometime in the future... But who knows when.. Here are some numbers on the bill mitchell 454 SBC

RPM LB-FT HP
4,000 559.3 426.0
4,100 564.8 441.0
4,200 574.0 459.0
4,300 579.4 474.3
4,400 581.7 487.3
4,500 584.0 500.3
4,600 582.0 509.7
4,700 580.5 519.4
4,800 581.2 531.2
4,900 578.8 540.0
5,000 574.7 547.1
5,100 572.1 555.5
5,200 571.8 566.1
5,300 569.3 574.5
5,400 564.8 580.7
5,500 555.0 581.2
5,600 544.2 580.3
5,700 535.3 581.0
5,800 527.0 582.0
5,900 521.4 585.7
6,000 516.4 590.0
6,100 510.8 593.2
6,200 509.7 601.7
6,300 506.4 607.4
6,400 500.8 610.2
6,500 489.9 606.3


What kind of power can you expect? The engine comes in an iron-head version advertised at 575 hp and 565 lb-ft, or an aluminum-head version that makes 600 hp and 575 lb-ft. Our test engine has aluminum heads, and we independently dyno'd it with an electric water pump and 13/4-inch-tube headers with 3-inch exhaust and Flowmaster mufflers to obtain the power numbers seen in the chart; the peaks were 610 hp at 6,400 rpm and 584 lb-ft at 4,500--that's 100 more horsepower and the same torque as a 502 Chevy! But 300lbs. less than a rat motor.. mabye even less with other light go fast goodies..