?'s for 454 swap in a 72 4x4 Blazer

[Big Bad 1972 Blazer]

Alright, now that I've almost got my 454 rebuilt, punched .060" and stroked .250" with a bunch of other goodies...I'm grunting right now (it'll be dyno'd soon), it's time to get the chassis ready to receive the beast. I'm looking for tips from others who've swapped in a BBC into a 4x Blazer. Towers & mounts used? Did you use a 73+ cross member? Clearance issues? Mods needed?

Here's some of the basics as to what I'm running w/ the BB...
TH350 W/ NP205
3" body, 4" suspension lift
tall valve covers for rocker arm clearance
Hedman long headers

Thanks in advance....I'll post pics when I'm done.

[6772king]

in mine I just used all the factory stuff and moved everthing ahead a couple of inches,,, downfall is you have to get all new driveshafts made,,, but mine were junk anyhow,,,they hit the road 1 two many times!!!!LOL!! and that was just with a little 327!! the 3 inch body lift will work in you favor also ,,,I can take pics of both setups ( with and without body lifts) if you want,,I have very tall valve covers on my blazer with no body lift

[Big Bad 1972 Blazer]

Originally Posted by 6772king

in mine I just used all the factory stuff and moved everthing ahead a couple of inches,,, downfall is you have to get all new driveshafts made,,, but mine were junk anyhow,,,they hit the road 1 two many times!!!!LOL!! and that was just with a little 327!! the 3 inch body lift will work in you favor also ,,,I can take pics of both setups ( with and without body lifts) if you want,,I have very tall valve covers on my blazer with no body lift

Did you shift everything forward to get enough clearance to the firewall? If so, where were the tight spots? Right now, I'll tend to massage the firewall to get enough clearance. I'd rather not spend more $$$ on my driveshafts, although it's not a big deal. I had to replace mine not to long ago due to an "unfortunate incident" with a log...lol Please post the pics with the body lift if you have them handy...gracias

[orangeuavol]

Take a look at the pics in my signature. I swapped the SB w/ a 402 BB. We used the SB mounts, existing cross member, and exhaust manifolds from a 72 Monte Carlo. All I did was recess two pockets in the firewall for valve cover clearance. Its a tight fit but was almost a drop in replacement. I will however have to have new driveshafts made because I put a TH400 and NP205 in place of the three speed dana 20 combo.

[6772king]

if you dont mind pounding the firewall in you wont have to move everthing ahead,,,I didnt want to do that,,,l'll try to get some pics tommarow,,, if I forget ,pm meand tell me i'm a a$$hole for forgeting LOL!!!

[MAC67]

this is the 468 i dumped into mine , i pulled the 350 , kncoked in to divits with a small hammer for valve cover clearance and walla bb blazer , it didnt bother me custom hammering the firewall ha ha ha , you can barely see them because they are hidden by the valve covers mostly heres a couple pics , i know theyr not real good

[Yukon Jack]

You will find some people have put bb's in their trucks and K5's with little to no modification and others that have to do alot. I fell in the "alot" catagory. Burt4x4 has a recent thread showing his bb he just installed - he hardly had to do any modification. I don't know why it fits so easily for some and not for others.

Here are pics of the modifications I had to make. And this is with a body lift. Would have taken serious pounding with a hammer to make the necessary clearance for me and these are short valve covers.





Here is a link to my webpage showing more pics and info on my bb swap

Big Block Swap

[Big Bad 1972 Blazer]

Thanks guys for the pics, tips, & links (my keyboard is acting up now from drooling at your rides).

The valve cover clearance was what I was worried about. Based on what I see, I think once I yank the SB, I'm just going to break out the cutting wheel and create a little clearance in the firewall....no reason not to. I've got a really good idea as to how much to hack out based on everybody's feedback. Murphy's law states that I'll probably be on the "lots of work side", so I might as well build in extra clearance in that area. It looks like nothing that a little fab work can't cure...and it if that doesn't work, I'll break out the 5lb hammer

[mister.freeze]

The Fox used to have a 454. Originally 350, then 454, back to 350, and now 383. No recesses were ever made to fenders or firewall. In fact, my SB sits on the 454 mounts. It looks like the original crossmember rivets were ground off, and it was moved AFT a ways and BOLTED back in. My distributor is tight to the firewall, and I've got about 8" between the pulleys and the radiator. If you need pix, holler.

[Burt4x4]

I used a '74 454 & '73+ SBC Crossmember(makes oil pan removable without moving the engine)

Kinda hard to see the firewall as I painted everything black, but I did have to BANG BANG BANG on the firewall just a lil bit to clear the driver's side head.

73+ crossmember sits infront of the oilpan instead of under it.

Some have had to notch the frame with a half moon shape to clear header pipe but mine is 1/8th away so i didn't have to notch it.
I plan on starting my 454 for the first time this Saturday
Good Luck
Burt

[Big Bad 1972 Blazer]

It really doens't suprise me to hear about so many differing accounts as to how much modifying needs to be drop in a BB, especially around the firewall. Shoot, back then, you could measure build variation in the assembly plants with a yard stick. Roll the dice....

Burt...good luck firing up the BB this weekend. I'm jealous, I 've got a few more weeks of work before I can crank mine over.