if you read my post on engine identification help i will try to make this shorter. found out the trans in my lesabre it a s.p.400, the riv. has a 455 and i found a 74 apollo. has anyone done this swap. i have heard that it would be difficult, no factory mounts availible for the x-body and 455, and no headers made that will fit. but i cant help to think that this would make a wicked combo. should woop-up on my regal with a chevy small block. any help would be great before i purchase the apollo, will most likely do it any way as i found it cheap and the buick bug has bitten me good. hope the wife dosent kick me to the couch. thanks.

All I know is that it has been done- I haven't done it myself, so I can't tell you what was involved.

Anyhow, I would imagine that as long as you get some motor mounts & frame brackets, you should be able to make it work. For exhaust, it sounds like either you will have to go with the stock manifolds (which can be ported out with great results) or custom-built headers, which can get pricey.

I love the S-P transmission, wouldn't trade it for anything!

-Bob Cunningham
bobc@gnttype.org

thanks for the info. are there any factory frame and engine mounts that will work for this swap? are the 350 mounts close? i guess the biggest problem i here is with the rear steer set up. there is a nova here in kc that has a LS1 and 6-speed in it, anybody seen it in the mags? rumor has it that he had to transplant a camaro/firebird subframe to go to front steeer and pull off the swap, but it was not a bolt in subframe swap. does anyone make a motor mount set up and header swap for the camaro/firebird subframe? smile.gif

just to let anybody who cares know, i bought the apollo and plan on attempting the swap, poston has headers listed for the f-body and a friend has a camaro subframe i can have if i go pick it up, but have still not found engine mounts, i know that some of the f-body's came with the 231 v-6, would these be close?? i am trying to contact the person here in k.c. that has the nova that he f-body subframed to install an LS1. if anybody wants to see his car check out hotrod oct 01 i saw this car on power tour and it was very impressive even if it is a chevy. i'll keep you updated, and if any one has any suggestion feel free. thanks

Have you tried TA Performance for the Frame and Engine mounts? Their phone number is (480)922-6807 and they are located in Scottsdale AZ.

Good Luck!

thanks, yea they told me that they did not have anything for this swap and informed me that none of the headers would fit, even their new shorty headers. not to worried about the mounts, should be easy to make. but the headers would be a different story. if i change the subframe to an f-body their headers will fit.

My project thus far: I installed a non-stage Catlin built Buick 455, .040 over in my 74 Apollo. Same engine @ 11.70 in my heavy stock 71 GS. Assembled a dummy block w/ oil pan and 400 short tail trans. case and positioned in the car as close to the firewall as I could. Bolted on engine brackets with std. fram pad mounts to the block and lowered in position. Care was taken to get the correct angles (side/side and front/back). With motor in position I welded mounts to main cross member. About 30% of frame pad mount extends over rear edge of crossmember so made some gussets supports and welded. Shallow part of stock oil pan w/baffled sump is right at 1" clearance above main crossmember. I think you could use stock tranny cross member but will have to drill additional bolt holes along subframe rail to relocate and bolt but study that one close . I had a local shop fab a tubular crossmember and welded in. This also cut weight and give me exhaust clearance. Various mfrs. make universal crossmembers that can be adjusted to frame and welded. NOW FOR THE STEERING/HEADER DILEMA! I'm using Skylark GS 455 headers by eliminating the frame mount str box and installing a Mustang II rack n pin. I looked hard at this. Can't do it with stock pwr str box but should with manual str box but you'll have to have headers custom made and my quote was 700-800 3 yrs. ago on headers only. Said no to that. I considered the small Flaming River Nova type manual box which should allow use of 1 7/8" Skylark headers....stop....doubt with bigger headers. F R Box with connects was high buck and still I wasn't satisfied. Came up with the idea of a Mustang II manual rack mounted to a fabricated tubular crossmember that replaces the orig. frame horn crossmember that sets in front of suspension cross member. Actually I left about 4" of orig. forward crossmember on both sides and boxed each. The fabricated tube crossmember has a flange plate welded at each end to bolt to the short boxed ends. Steering shaft has 2 knuckles and does go through the large crossmember to connect with rack. This set up allows me to use any Skylark big block header I want (have the equal length Mickey Thompson's on order from GSCA). My car is restored but built for street/bracket racing. Had to eliminate sway bar which ran where rack now rests. Car has 12 pt. roll cage with coil over shocks on all 4 wheels and ladder bars on rear. Car is well tied together so not sure if I'll need a sway bar for street. Steering arms were reversed using aftermarket performance tie rod ends with bushings that can be machined down to make rack's outer steering arms level with lower control arms. Bump steer.....don't forget that!"
Well that's pretty much it as far as motor/trans/headers. Currently wiring the car. Again, the dummy eng./trans setup, excluding me, really helped to set this car up. Body work and fuel system (280 Magnaflow w/15 gal. aluminum tank) are done. With other items being removed such as steel beams in doors and those heavy bumper shocks among others the car should not exceed 3100 lbs. Looking for mid-10's. Probably won't be any fuel available when it's ready for its maiden voyage. Hope you all understood this?