SBC Build Q's

[k5james]

High everyone, I'm new to this board and I'm currently building a 72 Blazer into a mild prerunner. I'm hoping to build an engine for it that can put out around 400-425 horsepower and roughly the same amount of torque. The Blazer is going to be used for street driving and high speed desert and dune running so I'll probably need most of the power between 2500-5500 rpms. The kicker is, since the truck will be spending
quite a bit of time in Mexico, I need it to run on 87 octane just in case I run out of gas down there and have to fill it up with Pemex. Is this something that can be pulled off? What compression ratio should I aim for to make it happen? I'd prefer to use AFR heads, which ones should I use? Any suggestions on a cam? Any info you provide would be greatly appreciated.

Thanks
James

Here's a pic of what it will be going in.

[subhuman415]

We will need to know gear ratios, transmisson, tires size, and weight to produce the best results.

[k5james]

subhuman415 said:

We will need to know gear ratios, transmisson, tires size, and weight to produce the best results.

Sorry about that. Gear ratio is 3.73, transmission is TH350 w/ stock stall tq converter, tires are 35x12.5x15, weight is roughly 4500-5000lbs, I haven't had a chance to weigh it yet.

[Mike Stark]

Build at least a 383" (400 would be better). 9.8:1 max with the aluminum heads and small hyd. cam. Good cooling system. Dual plane intake and vacuum sec. 750. The build should be pretty straight forward. Use the 190cc heads.

[Wolfplace]

Hi James,
Piece of cake with the AFR's
383 or 400, Keep compression at about 9.5 as Mike suggested,
An EDE Air Gap, hyd or hyd roller in the mid 270's to low 280's & you will have an easy 425+HP & 450 lbs ft without needing more than 6000 RPM & it should run on 87 no problem.
I recently did a 406 for a street deal with 195 AFR's, Isky hyd roller & 9.4 compression, EDE Air Gap & 750HP. We ran this on 91 & then on 87 with no difference in power.
From memory it was about 440HP & 480lb ft. This on a very "honest" dyno,, mine ;D
I can look it up if you want the exact numbers.

For info, AFR no longer makes the 190. You want the 195 for this.

If you email me I can probably save you a few dollars on the heads

[k5james]

Thanks Wolfplace, will do.