How durable are the transmissions in these cars?
It all depends on the transmission and what you do to it. A TH 350 is the strongest and it's a 3 speed. Th200 4R is pretty popular as it has the same 1-3 ratios as a TH350 but adds a .67 overdrive. It is not as durable in stock form as the TH350, but it can take a fair amount of abuse with some work. I run a stock one with 400+ ft lbs of torque and 350 hp at the crank ( estimated on computer)
What are some good sites to get aftermarket parts?
The biggest is Summit Racing for performance parts, restoration parts are more spotty.
What kind of cylinder compressioin should i get when doing a compression test on a 74 350 olds?
I would guess 125-150 psi on a stock 8.5:1 compression engine with a stock cam. The important thing to check for is variance between cylinders. more than 5-10 psi indicates the possibility of a problem. Unlike the 4G63 you likely had in the DSM, older V8 engines aren't too expensive to rebuild.
You start modifying these cars, whats the first thing to break?
Rear axle or transmission depending on what you have.
Any thing notorious for breaking on these cars? (I.E My 1990 eagle talon, if you didn't change the timing belt after 55k you would be replacing a head) Rear end when running slicks, power seat motor transmission, TH200C 3 speed trans ( V6 and weak V8 cars).
Is 325hp too much to ask out of these motors? How do i Get there reliably?
325hp is tame! You don't need much to get there, but you will need to rebuild the engine. You want no less than 9.5:1 compression, a dual plane intake, better heads ( stock or aftermarket), and a reasonable cam. If you have a Quadrajet and an HEI ignition, you can tune the parts you have and skip buying a new carb or distributor.
And last but not least.... how do you get these things to hook up? Mine just spins really well.
You need a limited slip diff. Which one you need depends on your gearing. There are "case breaks", meaning each diff is designed with a set of ratios it can run. Unlike a Ford, GM varied the differential carrier, mounting flange position rather than the ring gear thickness to compensate for the smaller pinion gear on lower ( numerically higher) geared vehicles. Look at S- trucks ( S-10, S-15, S-10 Blazer, S-15 Jimmy, Sonoma, Bravada) and F cars for a LSD. G bodies also sometimes had it too. Cars and trucks that have it will have a code G80 on the Service Parts Identification label.
It all depends on the transmission and what you do to it. A TH 350 is the strongest and it's a 3 speed. Th200 4R is pretty popular as it has the same 1-3 ratios as a TH350 but adds a .67 overdrive. It is not as durable in stock form as the TH350, but it can take a fair amount of abuse with some work. I run a stock one with 400+ ft lbs of torque and 350 hp at the crank ( estimated on computer)
What are some good sites to get aftermarket parts?
The biggest is Summit Racing for performance parts, restoration parts are more spotty.
What kind of cylinder compressioin should i get when doing a compression test on a 74 350 olds?
I would guess 125-150 psi on a stock 8.5:1 compression engine with a stock cam. The important thing to check for is variance between cylinders. more than 5-10 psi indicates the possibility of a problem. Unlike the 4G63 you likely had in the DSM, older V8 engines aren't too expensive to rebuild.
You start modifying these cars, whats the first thing to break?
Rear axle or transmission depending on what you have.
Any thing notorious for breaking on these cars? (I.E My 1990 eagle talon, if you didn't change the timing belt after 55k you would be replacing a head) Rear end when running slicks, power seat motor transmission, TH200C 3 speed trans ( V6 and weak V8 cars).
Is 325hp too much to ask out of these motors? How do i Get there reliably?
325hp is tame! You don't need much to get there, but you will need to rebuild the engine. You want no less than 9.5:1 compression, a dual plane intake, better heads ( stock or aftermarket), and a reasonable cam. If you have a Quadrajet and an HEI ignition, you can tune the parts you have and skip buying a new carb or distributor.
And last but not least.... how do you get these things to hook up? Mine just spins really well.
You need a limited slip diff. Which one you need depends on your gearing. There are "case breaks", meaning each diff is designed with a set of ratios it can run. Unlike a Ford, GM varied the differential carrier, mounting flange position rather than the ring gear thickness to compensate for the smaller pinion gear on lower ( numerically higher) geared vehicles. Look at S- trucks ( S-10, S-15, S-10 Blazer, S-15 Jimmy, Sonoma, Bravada) and F cars for a LSD. G bodies also sometimes had it too. Cars and trucks that have it will have a code G80 on the Service Parts Identification label.
