I know there are people on both sides of the 403 good or bad engine debate, but i wanted to start a thread for people who like and built these. if you have info and/or personal build experiance please post your builds, set up and 1/4 time. Also if you have managed to spit the crank out the bottom id like to know the story behind how it happened

 

http://realoldspower.prophpbb.com/topic5127.html

Just dyno and street time so far. Lots of good build posts on ROP

 

Here's mine. 79 403. No track time yet, only have a little over 300 miles on it since the build, so still kind of taking it easy on it. But it pulls very hard.

 

One more here;

0.024 KB's, zero decked, 0.036" Cometics, chamber 68.5cc, CR 11:1
#7 heads, big valves, "medium" porting, filled crossovers, Crane roller rockers.
Stock crank, conrods, ARP everywhere, balanced.
224/234 Edel RPM cam, straight up.
Davies Graig EWP+controller.
Rpm intake, cold air intake, 750 DB modded carb, 1 3/4 cheap headers, x-pipe, 2 1/2 full exhaust, 2 x dynomax turbo mufflers.

Th2004R, 3000+ 9.5" converter, 3.55:1 8.8" rear.

Tried 1/4 mile once (during standing mile run), 12.7 without warming tires. Car 3500lb with driver.

Trying Howards 235/245 0.050" with Rhoads v-max lifters for next summer. Wish hp to peak at 6000, now at 5500-5600.

 

im beginning to see .024 is a lot more common bore than I thought lol heres mine.
comp cam- .475/.48 lift //262/274 dur- part# 249-CL42-222-4
comp roller rockers 1.7
Eldebrock performer intake
stock 4A heads - shaved
Kb hyperutectic pistons
stock crank and rods
block decked and bored .024 over
Not sure on compression but i have to run atleast mid grade but i add super
1 3/4 primary ceramic headers
nitrous express mainline -100 shot with al safty's since i dnt have forged internals.
HV oil pump/ 8 qt oil pan
demon 750 annular discharge
holley blue regs for carb and nitrous
2.41 rear diff with th-350 and 2100 stall
Im looking to put 3.08 in it, I have a lot of trouble hooking in first with the 2.41 but id like a lil lower gear but ill be getting some drag raidials soon as well and see how they hook.

 

That is because the KB piston made for that bore (common to another poular engine, BBF, I think) is a good choice for a nice little 403 build, there really aren't many options.

 

Also does anyone have an idea on new heads i can get, i have dish top pistons -6cc and i finally figured my compression is about 9.7:1 give or take and thats with shaved 4a heads. all the other heads ive seen already have like 60cc and i dnt wanna get compression so high i cant run just super. im looking into geting aluminum heads but found a place that can custom make heads but im scared to call and get price lol

 

 

Edelbrock or checked over Procomp heads would be ideal with the 6cc dish pistons. 4A heads are awful heads without hours of port work. You will gain a good amount with a head swap.

 

well im looking into some heads and iv discoverd ima need to learn more about valve clearance, its been like 2 years since i had machine work done and ive lost the sheet with all the need too know numbers but if my memory is correct he zero decked the block, but before he did work he ask for cam info and rocker ratio so i assume he made it pretty close when he shaved the heads. im going to have to call him and hope he kept records, id hate to spend money on heads just to find out i got to get diff rockers or cam too but im assuming from what i been reading i will.maybe lower lift to clear and more duration to compensate??