489 10.51 SCR need cam help for pump gas

[Bowtieman427]

Hello son is 15, building a 489 BBC next semester in HS engine class. The 489 BBC will be for his 1983 1 ton 4x4 chevy K30 pick up 4 speed, 4.10 gears, solid axles dana 60 in front and GM 14 bolt in back. This is NOT a dully but a SRW. We are restoring it in hopes he can drive it to school and a car show or 2 use it to tow the Chevelle to the strip or get some firewood. He wants a BBC and wants it to make power all over this will be a street truck MUST run on pump gas. Not sure on the tuck weight but they are not light I bet over 5000 lbs

-2 bolt main 454 block. .030" over, zero decked
-10.51 : 1 compression (sorry the kit only has 20cc pistons for his budget)
-ProComp 300 oval heads.
-will have .039" Quench
We are going to get a complete Howards HR Cam kit lifters, springs, keepers, timing set, push rods We really like this cam
Howards 122115-12
278 /288 225 / 235 @ .050 with .595 .601 lift. 112 LSA and 108 IC like the upper HP and great low end torque. We are NOT sure this will run on pump gas given our SCR of 10.51 : 1 Howards recommended this and they also said we may consider
Howards 120205-12
286 / 298 233/245 @ .050 with .635 .635 lift 112 LSA and 108 IC but will lose bottom end torque vs the one above. or
Howards 120605-12
286 / 300 233/247 @ .050 .601 .612 lift 112 LSA and 108 IC

Any ideas on what Howards HR cam will work well with 10.51 compression and give us a great bottom end torque and run on pump gas ? Any suggestions remember this is a truck not a 3000lb car for the strip. We like the 278/288 but afraid it will not run on pump gas we have 87-91 octane here in MN.

 

[MikeB]

I'll chime in here since you haven't had any responses.

Without changing pistons or going to heads with bigger chambers, you will have to use premium gas, and maybe even Aviation gas or an octane booster. You could also try limiting mechanical and vacuum advance to below optimal levels.

Yes, you can get a big cam to bleed off compression, but then the engine will have low vacuum and crappy manners on the street. Then, at RPMs above where peak TQ occurs, you'll start getting better cylinder fill, bringing the compression ratio back into play. Back in the day, GM used wide LSAs (as much as 115) and high compression in its high-performance engines, but they still had to run premium, which was much higher octane than we have today at the pumps.

By the way, did you do any research on those ProComp heads? And I don't mean just reading the specs.