Was thinking of picking up a stock or mildly rebuilt '72 Riv 455 motor someone has with all accessories, brackets that came out of car with TH400. My car is '72 Skylark custom convertible original 3 on the tree car converted to Floor shift M 20 so all the 4 speed components are they for the 350 set up... runs good....just thinking of a BBB... So if the 455 engine comes with all pulleys, Alternator, AC and Power Steering brackets, as well as both engine and frame mounts..... what else would i need? Let's assume the crank is drilled... I assume clutch fork is different, will the M20, Driveshaft and crossmember be the same? What about other things to think of? Like do i need bigger front springs, different steering shaft... and would 2.5 exhaust be ok for a 300 HP 455? I assume the bell housing is the same? Thanks for any help!
455 which oil pan and pick up does it have ? Doubtful the drive shaft is the same. Big Block steering shaft is needed . The parts place has a reproduction if you cant find a used one.
A 350 z bar can be made to work with minor modifications. Done it twice. Block does need to be drilled for z bar stud. The crank may not be finish drilled for a pilot bearing, mine wasn't but i had a pilot bearing turned down to fit. Big block springs are recommended
I believe the drive shaft is the same too. I also used the 350 steering shafts in my conversions. I know there is a difference bit I'm. not really sure what it is.
The BB clutch rod that goes thru the firewall is also longer, and the clutch fork, and Z-bar are different. Plus the pivot pieces for the Big Block Clutch Fork. Duane
You can use the small block/ 442 style fork. It will fit and function. Yes, the upper rod on the BB is 3/4" longer but you can make up the difference with a longer adjuster rod if need be. TPP makes a BB z bar. I think they also make the bb upper clutch rod now. You'll need a BB flywheel and an 11" clutch set up And the pilot bearing will need t ok be turned down. In my case it was about .010 Steering shaft doesn't need to be replaced. The shaft won't know the difference.
I added a BBB in my all original 71 GS350 4 speed. Beside the BBB motor, flywheel, 11" clutch and motor mounts, the original m21 transmission, driveshaft, clutch linkage is all SBB.
Sweet. Did you change any front end parts, springs, shocks etc? I think i also need to add to the list a BBB fan shroud. Thanks
Since my GS was all original I did a compete nut and bolt frame/suspension restoration. So to answer your question yes I did add BBB front springs and BBB fan shroud.
As far as the clutch pedals, linkage (including fork) and bellhousing are concerned they will all work with the 455 4 speed. Grand Sports used unique clutch linkage parts that are not reproduced (except an incorrect zbar). Russ
OK, I want to level-set here. Please correct me where I'm confused. Factory original-appearing conversion not required. I'm just looking for a stable, working swap. I have a stock 71 350 4-speed GS currently with an M20 Muncie. I also have a 1970 block-based 455 with a tapped Z-bar shaft hole and what looks like a machined crank for a pilot bearing. If I pull the 350 and swap in the 455 with headers, I believe I will need the following at a minimum: Big block frame pads 455 flywheel 11" clutch Pressure plate I may or may not need: Modified pilot pushing Longer clutch rod? (Unsure from previous posts) Front springs (I'm hoping that headers and an aluminum intake balance out) Not correct for a factory original swap but will work as-is: 350 Z-bar 350 clutch rod? (Unsure from previous posts) 350 steering shaft 350 clutch fork Things that are the same and no change needed: Bell housing Muncie transmission Shifter and linkage Driveshaft Does that cover it?
Hi George, What Front Springes did you go with and how do you like them. Mine seem to soft. Thanks, Mike
You might need to play with the clutch linkage a bit parts wise to find something that works. I dropped a 70 455 into a 69 with TA Headers. The car was an original small block 4 speed car. I kept the small block clutch fork and small block upper clutch arm. I used a parts place repro big block z bar (the one with the bushing) and a random lower clutch adjuster I ordered off eBay. I tried several other combos of parts and this worked the best with getting the linkage to line up well, not hitting the headers etc. Hope this helps.
