The downshift at 30, does that feel the same as in our deVilles?



Now I know this is kind of a hard comparison, but does the low end power of the 425 compare to the low end power of the 4.9, or is it a totally different ballpark?

Oh, also, what grade of gas should I use? the guy I bought it from said it will run good on 87, but it runs better with 89.

I use the mid grade (89) if I use 87 she gets unhappy, runs but unhappy. Last week I spent $71 to fill her up!

I used to run premium (93) in mine, then I just started running regular (87) in it... no difference in performance or mileage... with 8.2:1 compression, it will run on regular just fine.

the 30mph run.... the 4.9 is quicker, lighter, better gearing etc... it was alot different with the 425, there is alot more mass its moving aorund, so it felt alot different... its a shame I can no longer compare the two.

Quote:
Originally Posted by purely_artificial
I drove a '81 Brougham Coupe once, it reminded me of that '90 Brougham D'Elegance 307 I drove....slow.
Chadillac,

You're talking about my poor old '81 Coupe that you drove last fall when it was sick. FYI, just got the V8-6-4 running properly, somehow, and the performance is greatly improved. Comparing the '81 with 368 FI to the '79 with 425 carb, I have to say I really like the fuel injection for the velvet smoothness but I love the brute feel of the 425. I wish my 425 had FI!

I love reading about Rick's performance testing on the '79 he had (sorry you lost it). I'm pretty much a chicken to pound my cars since they are old and I'm afraid I'll break them. That's probably bad thinking since they are over built Cads from the good old days!

I had lots of fun with that car... it never once gave me any problems.

I see it as, if its going to break, its going to break. But with a big block Cad, a Turbo400 and a GM 10-bolt 8.5\" rear end, all in a passenger car... the driveline is so solid, that breaking anything is really out of the question.

Plus, if it breaks, I would fix it... it was easy. For a 27 year old car with 93k miles, I still used it as a daily driver, and besides its thirst for gasoline, it never once even blinked.