85 buick riviera.

[Guest]

I just purchased an 85 Buick rivieara with a 5.0litre 307 v8 motor. Everything is stock and works perfectlly well. I would like to modify several things in the motor and transmission area to improve perfomance. Please advice on possible mods. I am willing to swap the motor with a more supped up one if I can get the right motor.

[ffinz1]

Just get motor trans fron a 79 or 80 riv they had 350's with 3SPd'sthen fabricate larger exhaust.the overdrive trans are a littla fragile. ot if you can find a trans from a riv turbo t type they have a 3.36 ratio

[Guest]

the 307 engine is a dog. i hate to say it, but you should do what the last guy states in his note. <P>i have one of these engines in my fathers 1989 chevy wagon. i drove it for 6 years. we still have it and it has 220,000 miles with no problems. but it is very hp deficient. i called modello's performance (he is a big olds engine guy-like ta perf. is for buicks). he said that the 403 olds engine from a trans am will bolt right in to where the 307 was. that, or the 79-80 buick 350 ransplant is the best cure for that 307.<P>john

[rocketraider]

Doesn't have to be from a TransAM. GM used Olds 403s in many cars from 1977-79, notably full-size Olds-Buick. Nice torquey small block, they just have a weaker block than earlier Olds engines due to the windowed main bearing webs. Good for up to about 5800-6000 rpm tops.<P>Agreed on 307 longevity. Drove one 178000 miles in an 81 Pontiac big wagon and it was still running well with no oil consumption when a Mitsubishi Eclipse took it out. But a long grade worked that engine to death. The Olds 350 in the Custom Cruiser that replaced it doesn't even breathe hard going up the mountain.