I am putting a Blueprint engines 454 in my 1987 V10 4x4. The Blueprint engine exhaust port on the heads is .30" higher than GM heads. I am told this can cause issues with plugs and plug wires being too close to the headers or the header will not fit because it hits the spark plugs. The other issue I have read about is big block verses small block engine perches, the part of the motor mount that attaches directly to the engine block. Does anyone know if there are two different perches, one for small block and one for big block? Do I need to find big block perches to make this engine fit? I already contacted LMC and they had no clue about big block verses small block motor mount perches. I am sure someone must have installed a Blueprint big block in a 4x4 square body. Any help is greatly appreciated!!
I have a 2WD truck (1966 GMC 1/2 ton) with a BBC with a Squarebody front crossmember.
I used Squarebody C20 clamshell mounts, which are different than SBC mounts.. especially the frame brackets.
In the original configuration with stock cast (781) cylinder heads… Hedman #69110 were a perfect fit.
However, an upgrade to Performance World aftermarket aluminum heads with 0.375” raised ports resulted in insufficient plug boot clearance. Boo.
I presently have a set of Patriot #H8054 Squarebody headers installed.
Plug boot clearance will work with 2500*F basalt plug booties.
Installation issues:
1.) it required the Vortec mini starter. No room for the stock Delco 10MT.
2.) the collectors are angled outward toward the frame, which is causing me grief with my 3” exhaust cutouts. Planning to rosebud the header tubes in front of the collectors and straighten them out.
3.) the dipstick is mounted on the RH side of the engine and goes into the oil pan. Welp, header tube #2 snakes under #4, and ends up almost completely blocking access to the oil pan dipstick boss!
I’m seeing both of the last two issues as straight up design flaws.
I have a set of Hedman #65002 (70-72 Chevelle application) on order and hoping for a better fit.