currently building a +.030 454 with dart 308 heads, was planning on running it NA but came across a deal on a 177 blower. can i run 5 psi safely if i can keep compression around 9-1? Im gonna run a 500 efi cam i have and the bottom end will be a forged stock crank, eagle h beams and forged weisco pistons. the carb is a hp500 holley and exhaust is a gil. any info is appreciated.

I had a 0.60 over 525SC which used the same blower as you have with 5.5 psi and 8.5:1. Worked well.
With 9:1 there is no room for error as the 177 creates heat. If timing and fuel is dialled in perfectly, I believe it will work however. There are intercoolers for the 177 out here..

What is your HP goal, at what RPM?

Dart 308 Int flow:

0.400" 291 CFM
0.600" 347 CFM

The exh port great as well.



9:1 with 5psi is about 12.2:1

Depending on where you are in your build, going with a stroker crank would yield a similar result and keep it simple. Lots of complications with a blower.

Unless you cool the A/F charge from the 177, you'll get diminishing results.

The 177 can flow enough air to get you 650hp if you use it well...after that it runs out of steam.

https://www.speed-talk.com/forum/viewtopic.php?t=46124

What can your drive handle?

hoping for 600 hp, under 6k rpm. a stroker cran would involve different length rods and changing pistons as compression height is different. i think changing pistons to drop compression to 8.75 to 1 is gonna be the ticket. thinking the speedpro 2399f will be the ticket.

Be wary of Speedpro...they're not what they once were..even from just a few years ago.

Icon as a Keith Black Solvolite l...would be a great budget Forged option. Lots of good tech in them...well priced.

I have a friend who has a similar ish build in a 22' Apache. Its a 460" Gen 6 roller engine block with 088 heads with inconnel exhaust valves and a nice Johnson Lifter set with a Custom spec'd cam and nice valve spring pack. He's on a 174 blower from B&M at 4-5 psi. Motor is 8:6:1. Mahle pistons. The motor has the AEM Methanol Injection kit set for boost to spray in a 1" carb spacer. It is a VERY nice setup. A well renowned engine builder spec'd it and it's proven to be a great package. It's been together for years and its really turn key as it gets.

As some said above, setup is critical and key and margin of error is thin with the setup. The motor was dyno tuned with meth so obviously losing that would be the margin of error becoming non existent. ​​​​​It has a engagement/on light on the dash. Works well. The motor pulls HARD. It made 663 HP & 682 lb ft.

I have 60 over 454's with roller cams, 088 heads with 177's and inter-coolers. Torque was insane, 640 at 2700 RPM to max 670 at 3900 with hp 620 at 5500. I don't know what the static compression ratio was.

what are you running for a carb, 4150 or 4500? im not opposed to running a intercooler, but will probably upgrade to a 250 or 256 in a year or so. what boost are you running?

I installed Holley snipers and Daytona ignitions, I did not check boost. I'll see if I had pulley sizes in my notes.
Looks like I ran a 7" bottom with a 3" top
The snipers worked well for me, I only did 40 hours before scrapping the boat.

Have the snipers proven themselves to be reliable? I’ve seen so many of them get sent back to Holley… that would make me pretty nervous.

Anyway, just curious.