does anybody know of a way to figure out more or less what kind of horsepower/torque an engine is putting out witha few mods? i have an oldsmobile 403 in a 78 trans am and i've done a few things to it and plan on few more as money permits. obviously you feel the differance but it would be cool know a ball park of what the differance is kind a before and after.. Thanks.

I get a chuckle out of the "bolt on up to 20 extra horses with our new and improved muffler bearing" ads.


There's no way to tell without a before and after dyno how much (or even if there was) improvement. You could make a good case for guestimates with time slips, but only if there were several before and after. The "seat of the pants dyno" or "butt dyno" means nothing.


I'm not saying your car isn't faster or more powerful, but you can't prove it's true or by how much.


C.J.

very well. thanks. another question have then. do you know if a set of 330 heads will work with my 403. i picked up a pair of cores for 150.00. the guy claimed i could use them to gain compression in my engine.. wich seems to be my biggest down fall with building any kind of respectable power.

403's 83cc heads give you an 8.2:1 CR, but they have slightly larger valves than 330 or 350 heads. Perhaps just getting your 4A heads reworked and shaved would be the best option.


Contact Terry at FCR racing. He's "the man" on 403s.


Before you bump up the top end "push", make sure you get the bottom end in order to handle it.


C.J.Edited by: texasred

OK RED. NOW YOU ARE SHOWING OFF.....GREAT INFO.

...and you'll have to get the earlier heads drilled to accept1/2" head bolts used on the 403.


NOW I'm showing off! [img]smileys/smiley2.gif[/img]


C.J.

that's awesome. thanks for the info. i'll check outFCR racing for sure. i've read many times about having to support the bottom end of these 403's because of thier windowed mains. mondello olds sells a prepped 403 short block with main girdel for like 4995.00 ouch! who said this hobby was cheap right? anyway thanks again red

No problem!


Allso, get Bob Gerometta' Oldsmobile Engine Modification and Tuning Guide. http://stores.ebay.com/Wild-About-Cars-and-Car-Stuff. I promise you won't be disappointed.


And (IMHO) stay away from Mondello. Since he let his son-in-law take over, their reputation is in the crapper. Terry's one of many good Olds men out there.


C.J.Edited by: texasred

OK RED .. YOU DA MAN. I ADMIT IT. NOW I AM GOING TO MY BASINETT AND PULL THE COVER OVER MY HEAD.

thanks again, great stuff!